simple conservation of mass experiment

Conservation of Mass Experiments

Start with reviewing the difference between physical and chemical changes. (Chemical changes include: gas, color change, precipitate, temperature change, or light). Get some play doh and roll it into a ball. Place it on the scale and ask students if they think the mass will change if you change the shape of the play doh. You could also use legos or anything else you have handy.

Once they’ve seen that physical changes don’t cause a mass change, move on to chemical changes. Here are some labs you can use for different grade levels to teach the law of conservation of mass.

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Mass Science Experiment For Kids

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Will the mass of a bag of microwave popcorn increase, decrease, or stay the same after it is popped? This simple mass science experiment for kids is a fun hands-on way to teach kids about the law of conservation of mass and about chemical reactions. Plus, they are rewarded with a delicious snack for all their hard work!

Getting Ready for Mass Science Experiment For Kids

This is such a quick and easy kitchen science experiment! We simply grabbed an unpopped bag of microwave popcorn and our kitchen scale. Then we were ready to go. That was it!

Popcorn Science Experiment

I asked my kids if they thought the mass of a bag of popcorn would change after it was popped. My kids were all over the map with their answers!

One of them thought that since the unpopped kernels are smaller they should weigh less than popped kernels while another thought the popped kernels should weigh less since they are less dense. They were excited to find out what would happen.

We tared the kitchen scale to zero and then placed the unpopped bag of popcorn on the scale. Our bag weighed 98 grams. We removed the bag, tared the scale, and weighed the bag a few times to ensure that our measurement was accurate.

To pop the microwave popcorn we followed the directions on the package . Ours called for 2 minutes in the microwave on high, but the time may vary depending on the brand of microwave popcorn that is used.

Once the popcorn was finished popping we pulled the bag out of the microwave and weighed it again . We were all a little bit surprised that the mass read 93 grams! We reweighed the bag a few times just to be sure, but we found that the measurement was correct.

The bag of popcorn lost about 5 grams of mass when it was popped.  Defiantly a great mass science experiment for kids!

When we opened the bag a bunch of steam escaped. We weighed the open bag of popcorn again and found that it had lost even more mass! So cool!

The Science Behind the Mass Science Experiment For Kids

Where did the mass go? Did it disappear?

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction . This means that no matter how a material changes, the mass will remain the same if the system is closed during the reaction.

Ideally, if the bag of popcorn was completely sealed the mass would be exactly the same before and after it was popped. However, since there are small holes in the bag, steam escapes. This makes the mass decrease.

Popcorn kernels contain a small amount of water that turns into hot steam when the kernels pop. The more of this steam that escapes, the more the mass of the bag decreases. This is why the mass decreased even more when we opened the bag!

Need More Science Ideas? 

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Magic Milk Experiment 

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Wait, Weight, Don't Tell Me!

A simple chemistry experiment—adding baking soda to vinegar—seems to challenge the law of conservation of mass.

Video Demonstration

• Safety goggles
• Baking soda (sodium bicarbonate)
• Vinegar (standard 5% acetic acid)
• Flask or bottle
• Measuring cup
• Balance scale that reads to at least 0.1 gram
• Optional: extra materials to experiment with, such as more balloons, zip-seal sandwich bags, 2-liter plastic bottles, etc.

• Put on your safety goggles.
• Attach a balloon to the end of the funnel.

• Pour about 1/2 cup (120 mL) of vinegar into the bottle or flask.

To begin, carefully put the sealed flask onto the scale and write down its starting weight.

You’re about to tip the balloon’s contents into the flask. What do you think will happen? Will the weight go up, down, or stay the same? Why?

Write down the final weight when the reaction is over.

Surprise—your balloon swelled enormously, but the weight actually dropped.

This result is especially confounding if you happen to be familiar with the law of conservation of mass : In any closed system, mass is neither created nor destroyed by chemical reactions or physical transformations. In short, the mass of the products of a chemical reaction must equal the mass of the reactants.

Did you really just violate the law of conservation of mass? You might be dying to know what’s going on, but wait, weight—why not figure it out for yourself?

The answer is below…but to avoid a spoiler, skip down to the Going Further section before reading on.

Alright, here’s the answer: Besides the chemical reaction, the only thing that changed in your sealed system was the volume . When you added the baking soda to the vinegar, the two combined to make carbon-dioxide gas, which inflated the balloon.

The expansion of the balloon changed the weight of your sealed flask because you and your entire experiment are submerged in a fluid: air.

Just like water, air is a fluid, and fluids buoy up objects. The upward buoyant force on any submerged object is equal to the weight of the fluid displaced by that object—this is known as Archimedes’ principle . By increasing the volume of your sealed flask, you cause it to displace more air, increasing the buoyant force on it and reducing its weight. Here's the thing to remember: Scales measure weight, not mass. The mass stayed the same due to the law of conservation of mass, but because of buoyancy, the weight went down!

Consider possible explanations for the weight change: Did the balloon leak? Did something funny happen to the scale? What else might be going on? Plan an experiment to test your theory, gather equipment, and carry it out.

For an illuminating variation on the original experiment, try combining your chemicals while they’re sealed inside a 2-liter bottle. Getting things to mix only after you’ve sealed the bottle is an engineering design challenge unto itself. Caution: Do not exceed the recommended amounts of 1/2 cup (120 mL) vinegar and 2 teaspoons (10 mL) baking soda.

To confirm Archimedes’ principle, measure the volume of the balloon and use the known density of air (0.001225 g/cm 3 at 15° C at sea level) to calculate exactly the weight of air displaced by your expanding balloon. Does the weight loss of your flask match the theoretical prediction?

This activity is meant to spark more experimentation. Having a variety of supplies on hand will allow for creative investigation into this phenomenon.

This idea was first introduced to us by visiting fellow Eleanor Duckworth of Harvard University.

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Law of Conservation of Mass

The Law of Conservation of Mass is a fundamental concept in chemistry, stating that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law, the mass of the reactants in a chemical reaction equals the mass of the products . Further, the number and type of atom s in a chemical reaction is the same before and after the reaction.

Definition and Statement of the Law of Conservation of Mass

The Law of Conservation of Mass was first articulated by Antoine Lavoisier in the late 18th century. It asserts that the total mass of a closed system remains constant over time. This principle is widely applicable in chemical reactions and also applies to other disciplines.

Applicability of the Law

The law holds true in chemical reactions under ordinary conditions. This is because chemical reactions only involve electrons and do not affect the identities of the parts of the atom .

However, the Law of Conservation of Mass does not hold in nuclear reactions, where mass can convert into energy (and vice versa) according to the principle of mass-energy equivalence as proposed by Einstein in the theory of relativity. This conversion occurs in nuclear fission and fusion reactions and some forms of radioactive decay.

Also, the law applies to isolated systems. If matter or energy enters or exits a system, mass may not be conserved.

Historical Overview

The concept of mass conservation dates back to ancient Greece. Mikhail Lomonsov, outlined the principle in 1756. Lavoisier gets credit for formalizing the law in 1773. His work disproved the then-popular theory of phlogiston , a supposed fire-like element released during combustion. Lavoisier demonstrated that combustion results from chemical reactions with oxygen, not from releasing a mysterious substance, and that the mass before and after the reaction was the same.

Examples in Chemical Reactions

Chemical reactions clearly illustrate the Law of Conservation of Mass. Chemists apply the law in balancing chemical equations.

• Combustion: In a simple combustion reaction , such as burning methane (CH₄), the total mass of methane and oxygen equals the mass of the resulting carbon dioxide and water. CH 4​ + 2O 2 ​→ CO 2 ​ + 2H 2 ​O (4 H, 1 C, 4 O atoms on each side of the reaction arrow.)
• Synthesis: When hydrogen and oxygen gases react to form water, the mass of the two gases equals the mass of the water produced. 2H 2 ​+ O 2 ​ → 2H 2 ​O (4 H and 2 O on both sides of the reaction arrow.)

Examples in Organisms

In biological systems, the law applies to metabolic processes. For example, in photosynthesis , plants convert carbon dioxide and water into glucose and oxygen. The total mass of carbon dioxide and water used equals the mass of glucose and oxygen produced:

6 CO 2  + 6 H 2 O → C 6 H 12 O 6  + 6 O 2

On a larger scale, the law applies to the mass of a human body, which encompasses numerous chemical reactions occurring at once. If you maintain a constant weight, the mass you gain from breathing, eating, and drinking equals the mass lost through breathing, perspiration, urination, and defecation.

Examples in Ecosystems

In ecosystems, the law is evident in nutrient cycles, such as the carbon cycle. Carbon atoms are conserved as they move through different components of the ecosystem, including the atmosphere, hydrosphere, lithosphere, and biosphere. For example, the photosynthesis reaction takes carbon from the air and fixes it into a glucose molecule. Photosynthesis does not create mass, nor is any lost in the process.

• Okuň, Lev Borisovič (2009). Energy and Mass in Relativity Theory . World Scientific. ISBN 978-981-281-412-8.
• Pomper, Philip (1962). “Lomonosov and the Discovery of the Law of the Conservation of Matter in Chemical Transformations”. Ambix . 10 (3): 119–127. doi: 10.1179/amb.1962.10.3.119
• Whitaker, Robert D. (1975). “An historical note on the conservation of mass”. Journal of Chemical Education . 52 (10): 658. doi: 10.1021/ed052p658

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Lesson 4.1 - Conservation of Mass

Lesson overview for teachers.

View the video below to see what you and your students will do in this lesson. 

Youtube ID: AqrzrUVcA50

Lesson Plan (PDF)   |   Student Activity Sheet (PDF)   |  Student Activity Sheet Answers (PDF)   |   Student Reading (PDF)   |   Teacher Background (PDF)   |   Connections to NGSS (PDF)

Students will be able to make measurements showing that whether the process is a change of state, dissolving, or a chemical reaction, the total mass of the substances does not change. 

Note: In the demonstrations and activities in this lesson, substances will be weighed before and after various processes have occurred – either melting, dissolving, or a chemical reaction. The basic principle students should observe and conclude is that mass is conserved in these processes, so the mass should not change. Students may observe slight variations of plus or minus 0.1 grams, depending on the sensitivity of the balance or whether the mass is actually somewhere between two values. If there is a minor change in mass, explain to students that small differences may be caused by a slight lack of precision in the scale readout, or by errors in the weighing methods, but that the overall results suggest that mass is conserved in all of these processes. 

Key Concepts

• When a substance changes state, the mass of the substance does not change.
• When a substance dissolves in a liquid, the total mass of the substance and the liquid it dissolves in does not change.
• When substances react to form new substances as products, the mass of the products is the same as the mass of the reactants.

NGSS Alignment

• NGSS 5-PS1-2:  Measure and graph quantities to provide evidence that regardless of the type of change that occurs when heating, cooling, or mixing substances, the total weight of matter is conserved.

Note: In this lesson, students measure and observe that mass is conserved during the processes of melting, dissolving, and chemical change. The students will not make a graph. 

• Students check to see whether the mass of ice and water in a cup changes as the ice melts.
• Students also test whether the combined mass of sugar and water changes after sugar is dissolved in the water.
• As a demonstration, students will observe that a precipitate forms in a reaction between solutions of magnesium sulfate and sodium carbonate, and that the mass of the products is the same as the mass of the reactants.

Download the student activity sheet (PDF)  and distribute one per student when specified in the activity. The activity sheet will serve as the Evaluate component of the 5-E lesson plan.  

Make sure you and your students wear properly fitting safety goggles.  Sodium carbonate may cause skin and serious eye irritation. Follow all safety precautions regarding the use, storage, and disposal of sodium carbonate. 

Clean-up and Disposal 

Remind students to wash their hands after completing the activity. All common household or classroom materials can be saved or disposed of in the usual manner. 

Materials needed for each group

• 1 Clear plastic cup
• 1 Teaspoon of sugar

Materials for the ENGAGE demonstration 

Materials for the extend demonstration .

• 2 Clear plastic cups
• Sodium carbonate
• Magnesium sulfate (Epsom salt)
• Graduated cylinder

1.  Do a demonstration to show that melting ice in water does not cause the mass of the combined water and ice to change.  

Question to investigate: will the combined mass of water and ice stay the same as the ice in the cup melts  .

• Pour water into a clear plastic cup so that it is about 1/3-full.
• Add 1 piece of ice.

Ask students: 

• If we weigh this cup with the water and ice, do you think the combined mass will change as the ice melts? No.
• Why or why not? Because the ice is just melting. It is still the same amount of water, but it’s just changing from a solid to a liquid. It should have the same mass.

Note: It is possible that some water may evaporate from the cup as the ice melts, causing the contents of the cup to weigh a little less at the end of the process. On the other hand, any water condensing on the outside of the cup could make it weigh a little more. Neither of these factors is likely to contribute much to the combined mass measurements, since very little water will evaporate or condense in the time it takes for the ice to melt.  

• Weigh the cup, water, and ice. Record the combined mass on the activity sheet. 

While the ice melts, have students conduct the experiment below. When they are done with that experiment and the ice has melted, show students the mass of the water and melted ice.  

Expected results 

The mass should be the same. 

Give each student an Activity Sheet (PDF). Students will record their observations and answer questions about the activity on the activity sheet. 

2. Have students weigh water and sugar before and after the sugar dissolves.

Question to investigate:  will the combined mass of sugar and water be the same after the sugar dissolves in the water  , ask students:.

• If you weigh a cup of water and a teaspoon of sugar and then dissolve the sugar in the water, do you think the mass will change? No.
• Why or why not? Because the same amount of sugar is still there. The solid sugar crystals break apart in water as the sugar dissolves, but the individual sugar particles or molecules are still present and do not change as a result of dissolving in the water. The combined mass of the sugar and water shouldn’t change.

Materials for each group: 

• Add water to the cup until it is about 1/4-full.
• Add 1 teaspoon of sugar to the water. 
• Weigh the cup with the water and sugar and record the mass.

Note: Evaporating water could make the water and sugar weigh a little less. This will probably not be a factor since very little water will evaporate in the time it takes for the sugar to dissolve. 

• Carefully swirl the cup to help the sugar dissolve.
• When the sugar is dissolved, place the cup back on the scale to measure the mass.

Expected results

The combined mass does not change.

• Did the mass change? No.

3. Do a demonstration to see if the mass changes during a chemical reaction.

Question to investigate: will the mass change when reactants combine to form products in a chemical reaction  , materials for the demonstration.

• In a clear plastic cup add 50 mL of water and 1 teaspoon of Epsom salt (magnesium sulfate). Gently swirl the cup so that the Epsom salt dissolves.
• Measure the combined mass of the cup with the Epsom salt solution in it. Tell students the mass and have them record it.
• To another cup, add 50 mL of water and add 1 teaspoon of sodium carbonate. Gently swirl the cup until the sodium carbonate dissolves.
• Measure the combined mass of the cup with the sodium carbonate solution in it. Tell students the mass and have them record it.
• Have students add the two masses together and record and announce the sum. 
• Hold the cups up so students can see them and then slowly and carefully add the sodium carbonate solution to the Epsom salt solution.

A white solid will form. At first the solid may appear or look like clouds of white particles floating in the liquid, but the particles should eventually settle out to form a solid precipitate at the bottom of the cup.  

Tell students that a chemical reaction took place and that a new substance, a solid, was formed.  

• Do you think the total mass of the two cups, the combined solutions, with the white solid will be more, less or the same as it was before the reaction took place? Same.

• Place both cups on the scale to measure the total mass. 

The total mass should be the same as the sum of the individual masses recorded before the contents of the cups were combined and the reaction took place.

Explain that the reactants have been transformed into a new substance, but that all the individual atoms making up the reactants are still present in the products. That’s why the mass stays the same.

4. Show an animation to help explain why mass is conserved in melting, dissolving, and in a chemical change.

Show the animation  Conservation of Mass in Physical and Chemical Changes.

Explain that whether a process involves melting, dissolving, or a chemical reaction, all the atoms that were there before the process takes place are still there after any changes have occurred, so the overall mass stays the same. 

5. Show an animation to help explain why mass is conserved when water is frozen.

Remind students that they observed that the overall mass of water and ice stayed the same as the ice melted.

• When water freezes to form ice, it takes up more room in the container, but does its mass change?  Even though the volume of water changes as it becomes ice, the mass of the water should remain the same before and after it turns into ice.

Show the animation  Mass is Conserved in Freezing . 

Explain that even though water takes up more room when frozen, the same number of water molecules are still there so the mass stays the same. 

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The Conservation of Mass

The Law of Conservation of Mass

The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction. If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system. Lavoisier's finding laid the foundation for modern chemistry and revolutionized science.

The Law of Conservation of Mass holds true because naturally occurring elements are very stable at the conditions found on the surface of the Earth. Most elements come from fusion reactions found only in stars or supernovae. Therefore, in the everyday world of Earth, from the peak of the highest mountain to the depths of the deepest ocean, atoms are not converted to other elements during chemical reactions. Because of this, individual atoms that make up living and nonliving matter are very old and each atom has a history. An individual atom of a biologically important element, such as carbon, may have spent 65 million years buried as coal before being burned in a power plant, followed by two decades in Earth's atmosphere before being dissolved in the ocean, and then taken up by an algal cell that was consumed by a copepod before being respired and again entering Earth's atmosphere (Figure 1). The atom itself is neither created nor destroyed but cycles among chemical compounds. Ecologists can apply the law of conservation of mass to the analysis of elemental cycles by conducting a mass balance. These analyses are as important to the progress of ecology as Lavoisier's findings were to chemistry.

Life and the Law of Conservation of Mass

Ecosystems can be thought of as a battleground for these elements, in which species that are more efficient competitors can often exclude inferior competitors. Though most ecosystems contain so many individual reactions, it would be impossible to identify them all, each of these reactions must obey the Law of Conservation of Mass — the entire ecosystem must also follow this same constraint. Though no real ecosystem is a truly closed system, we use the same conservation law by accounting for all inputs and all outputs. Scientists conceptualize ecosystems as a set of compartments (Figure 2) that are connected by flows of material and energy. Any compartment could represent a biotic or abiotic component: a fish, a school of fish, a forest, or a pool of carbon. Because of mass balance, over time the amount of any element in any one of these compartments could hold steady (if inputs = outputs), increase (if inputs > outputs), or decrease (if inputs 2 . Mass balance ensures that the carbon formerly locked up in biomass must go somewhere; it must reenter some other compartment of some ecosystem. Mass balance properties can be applied over many scales of organization, including the individual organism, the watershed, or even a whole city (Figure 4).

Mass Balance of Elements in Organisms

Each organism has a unique, relatively fixed, elemental formula, or composition determined by its form and function. For instance, large size or defensive structures create particular elemental demands. Other biological factors such as rapid growth can also influence elemental composition. Ribonucleic acid (RNA) is the biomolecular template used in protein synthesis. RNA has a high phosphorus content (~9% by mass), and in microbes and invertebrates RNA accounts for a large fraction of an organism's total phosphorus content. As a result, fast-growing organisms such as bacteria (which can double more than 6 times per day) have especially high phosphorus content and therefore demands. By contrast, among vertebrates structural materials such as bones (made of calcium phosphate) account for the majority of an organism's phosphorus content. Among mammals, black-tailed deer ( Odocoileus columbianus ; Figure 6) have a relatively high phosphorus demand due to their annual investment in calcium- and phosphorus-rich antlers. Failure to meet elemental demands can lead to poor health, limited reproduction, and even extinction. The extinction of the majestic Irish Elk ( Megaloceros giganteus ) is thought to have been caused by the shortened growing season that occurred during the last ice age, which reduced the availability of the calcium and phosphorus these animals needed to grow their enormous antlers.

Obtaining the resources required for metabolism, growth, and reproduction is one of the central challenges of life. Animals, particularly those that feed on plants (herbivores) or detritus (detritivores), often consume diets that do not include enough of the nutrients they need. The struggle to obtain nutrients from poor quality diets influences feeding behavior and digestive physiology and has led to epic migrations and seemingly bizarre behavior such as geophagy (feeding on materials such as clay and chalk). For example, the seasonal mass migration of Mormon crickets ( Anabrus simplex ) across western North America in search of two nutrients: protein and salt. Researchers have shown that the crickets stop walking once their demand for protein is met (Figure 7).

The flip side of the struggle to obtain scarce resources is the need to get rid of excess substances. Herbivores often consume a diet rich in carbon — think potato chips, few nutrients but lots of energy. Some of this material can be stored internally, but this is a limited option and excess carbon storage can be harmful, just as obesity is harmful to humans. Thus, animals have several mechanisms for getting rid of excess elements. Excess nutrients are released in feces or urine or sometimes it is respired (i.e., released as carbon dioxide). This release of excess nutrients can influence both food webs and nutrient cycles.

Mass Balance in Watersheds

Ecologists have often used naturally delineated ecosystems, such as lakes or watersheds, for applying mass balances. A forested watershed receives inputs of carbon through photosynthesis, inputs of nitrogen from nitrogen-fixing bacteria, as well as through the deposition of atmospheric nitrogen, inputs of phosphorus from the slow weathering of bedrock, and inputs of water from precipitation. Outputs include gaseous pathways (e.g., H 2 O losses through evapotranspiration, CO 2 production as respiration, N 2 produced by denitrifying bacteria) and dissolved pathways (nutrients and carbon dissolved in stream water). Outputs also include material transport across ecosystem boundaries, such as the movement of migratory animals or harvesting trees in a forest.

The Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA, has been the site of ecosystem mass balance studies since the 1960s. This landscape has similar-sized, discreet watersheds drained by streams and underlain by impermeable bedrock. By installing V-notch weirs, investigators could precisely and continuously measure stream discharge. By measuring the concentration of nutrients and ions in stream water, they could quantify the losses of these materials from the ecosystem. After calculating inputs to the ecosystem (by sampling precipitation, dry deposition, and nitrogen fixation), they could also construct mass balances. Additionally, researchers could experimentally manipulate these watersheds to measure the effects of disturbance on nutrient retention. In 1965, an entire experimental watershed was whole-tree harvested, resulting in large increases in nitrate and calcium losses relative to an uncut reference watershed (Figure 8). By studying inputs and outputs, an understanding of the internal functioning of the ecosystem within the watershed was obtained.

Figure 8: An experimental reference watershed at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA Researchers have manipulated entire watersheds, for example by whole-tree harvesting, and then monitored losses of various elements. The whole-tree harvesting of watershed 2 in 1965 affected the uptake and loss of nutrients and elements within the forest ecosystem and was followed by high loss rates of nitrate, hydrogen ions, and calcium ions in stream waters for several years. (Stream chemistry data were provided by G. E. Likens with funding from the National Science Foundation and The A. W. Mellon Foundation.) © 2011 US Forest Service .

Mass Balance in Human-Dominated Ecosystems

Mass balance constraints apply everywhere, even to highly altered ecosystems such as cities or agricultural fields. Cities import food, fuel, water, and other materials and export materials such as manufactured goods. Cities also produce large quantities of waste products — with solid waste sent to landfills, CO 2 (and other pollutants) produced from the combustion of fossil fuels being released to the atmosphere. Nutrients from sewage and from fertilizer runoff can end up in rivers where they will fertilize downstream aquatic ecosystems.

Human agricultural systems can also be analyzed using a mass-balance, ecosystem approach. Traditional agricultural practices emphasized efficiency, with most production staying on the farm — food for livestock was produced on the farm, food for farmers' families was produced on the farm, and plant and animal waste was composted for use as fertilizer on the farm. As a result, the amount of material cycling within the farm "ecosystem" was large relative to the inputs and outputs to the system (a relatively closed ecosystem). By contrast, modern industrial agriculture emphasizes maximizing yields over efficiency. Farmers import fertilizer in large amounts (often far exceeding the amounts that crops can use) and grow and export commodity crops. Ironically, in these highly open ecosystems (where inputs and outputs can far exceed internal cycling), food for farmers' families must often be imported as well. Highly productive agricultural systems are critical in feeding the world's growing human population, but as many of the ingredients of modern agriculture (e.g., water, petroleum, phosphorus) become increasingly limiting over the next century (due to depleted geologic deposits), we will be faced with the challenge of increasing the efficiency of these systems. Just as the constraints of mass balance provide a useful tool for ecologists in studying natural ecosystems, mass balance also ensures that the increase in human population and material consumption that has characterized the past 200 years cannot continue indefinitely.

References and Recommended Reading

Chapin, F. S. et al . Principles of Terrestrial Ecosystem Ecology . New York, NY: Springer, 2002.

Likens, G. E. & Bormann, F. H. Biogeochemistry of a Forested Ecosystem . 2nd ed. New York, NY: Springer-Verlag, 1995.

Moen, R. A. et al . Antler growth and extinction of Irish Elk. Evolutionary Ecology Research 1, 235–249 (1999).

Sterner, R. W. & Elser, J. J. Ecological Stoichiometry: The Biology of Elements from Molecules to the Biosphere . Princeton, NJ: Princeton University Press, 2002.

Simpson, S. J. et al. Cannibal crickets on a forced march for protein and salt. Proceedings of the National Academy of Sciences of the USA 103, 4152-4156 (2006).

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Conservation of mass.

Experiment #1 from Middle School Explorations: Chemical Reactions

Introduction

Students are introduced to chemical reactions through an Alka-Seltzer ® and water reaction. Prior knowledge is used to predict what happens when the two are mixed. Conservation of mass and evidence of chemical reactions are explored.

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This experiment is #1 of Middle School Explorations: Chemical Reactions . The experiment in the book includes student instructions as well as instructor information for set up, helpful hints, and sample graphs and data.

Conservation of mass

Describe what is meant by 'conservation of mass' and apply this to chemical and physical changes.

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Lesson details

Key learning points.

• Describe the conservation of mass related to the atoms in a reaction
• Describe a practical method to show the conservation of mass
• Show the conservation of mass in chemical equations

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

Starter quiz

6 questions.

balance -  

measuring masses

crucible -  

container for burning magnesium

bunsen burner -  

for burning the magnesium

for holding the clay triangle above the heat

clay triangle -  

for holding the crucible above the heat

Lesson appears in

Unit science / atoms and the periodic table.

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Conservation of mass in dissolving and precipitation | 11-14 years

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Explore what happens during precipitation reactions and when substances dissolve using this lesson plan with downloadable activities for 11–14 year olds

This simple practical activity challenges students’ thinking about mass conservation when substances dissolve or when chemical reactions produce precipitates. Working in small groups they carry out a simple experiment and agree answers to questions.

Learning objectives

Students will be able to explain that:

• Mass is conserved during dissolving.
• Mass is conserved during a precipitation reaction.
• Whatever change occurs, the total mass of the substances involved does not change.

Sequence of activities

Introduction.

Introduce the topic, and the learning objectives, by explaining to the students that they are going to look at two events which:

• People often explain using different ideas.
• They will come across a lot in chemistry, so they need to understand them correctly.

Activity: stage 1

Give each student the worksheet, ‘Dissolve and precipitate’.

Organise the students into groups of three. Give each group one flask labelled ‘Dissolve’.

Circulate and support with prompts as groups:

• Work on the dissolving task.
• Discuss the results and agree on an explanation.
• Elect a spokesperson to explain their group’s reasoning to the rest of the class.

Allow about 15 minutes for the groups to complete the task.

In a plenary:

• Draw out, in feedback from each group, their understanding that mass is conserved when substances dissolve.

Explain that in the next task they are going to test another event.

Activity: stage 2

Give each group one flask labelled ‘Precipitate’.

• Work on the precipitation task.
• Draw out, in feedback from each group, their understanding that mass is conserved when a precipitate forms.
• Ask students to reflect how their thinking changed while doing the experiments and to write this on the reverse of the worksheets.
• Collect in the worksheets.

In giving written feedback:

• Point out where students’ individual ideas are incorrect.
• Support and encourage students in changing their thinking to a scientifically correct viewpoint.

The idea of mass conservation is central to developing good understanding of chemical reactions. By sharing their ideas in ‘safe’ groups, students can progress towards scientific understanding in a supported way.

Feedback to the class enables the teacher to assess whether groups have understood the key concept.

Written feedback can pinpoint students who still need to change their thinking and encourage those who have developed the correct view.

Practical notes

For the prepared flasks labelled ‘dissolve’ (see ‘health, safety and technical notes’, notes 3 and 4).

• Conical flask, 500 cm 3
• A small tube to fit comfortably inside the flask
• Stoppers to fit the flask tightly
• Water, about 150 cm 3  in the flask
• About 5–10 g of one of these solids in the small tubes: sodium chloride, sugar, copper(II) sulfate (HARMFUL)

For the prepared flasks labelled ‘Precipitate’ (see ‘Health, safety and technical notes’, notes 3 and 5)

• Pairs of solutions at 1 mol dm -3 that form a precipitate on mixing (for example, sodium sulfate / barium nitrate (HARMFUL and OXIDISING), potassium iodide / lead(II) nitrate (TOXIC), ammonium phosphate / calcium chloride (IRRITANT))

Other equipment

• Access to a balance weighing to 0.01 g

Health, safety and technical notes

• Read our standard health and safety guidance .
• It is the responsibility of the teacher to carry out appropriate risk assessments.
• To prepare the flasks, tie the thread around the necks of the small tubes. Ensure that the length of the thread supports the tube in an upright position in the flask, but allows the contents to mix when the flask is tilted without being opened.
• Put the chosen solid into the tube. Put about 150 cm 3 of water in the flask. Use the thread to arrange the prepared tube in the flask so that the contents mix when the flask is tilted. Label the flask ‘Dissolve’.
• Put the chosen solution (10–20 cm 3 ) into the tube. Put the second solution in the flask. Use the thread to arrange the prepared tubes in the flask so that the contents mix when the flask is tilted. Label the flask ‘Precipitate’.

Principal hazard

• Stoppers insecure in flask, leading to spillage.

Alternative strategy

If time and/or resources are short, the teacher can demonstrate the chemical events. Groups can discuss the results and make their predictions as suggested.

The mass values should remain unchanged during dissolving and precipitation. Responses should reflect this.

Primary teaching notes

If you teach primary science, see the guidance below to find out how to use this resource.

Skill development

Children will develop their working scientifically skills by:

• Asking their own questions about scientific phenomena.
• Using a range of scientific equipment to take accurate and precise measurements or readings.
• Using appropriate scientific language and ideas to explain, evaluate and communicate their findings.

Learning outcomes

Children will:

• Observe that some materials will dissolve in liquid to form a solution, and describe how to recover a substance from a solution.
• Demonstrate that dissolving, mixing and changes of state are reversible changes.

Concepts supported

Children will learn:

• That some materials dissolve to form a solution.
• That materials are still present when they have dissolved and that they haven’t disappeared.
• That mass is conserved when dissolving and precipitating.

Suggested activity use

This activity can be used as a whole class investigation into the dissolving and precipitation processes, with children working in small groups to observe and answer the questions given. Alternatively, the activities could be demonstrated by an adult to stimulate discussion and questioning.

Practical considerations

It is important that the key vocabulary ‘dissolve’ and ‘precipitate’ are understood correctly by children in the introduction of this activity.

The ‘Dissolve’ task is more relevant to the primary science curriculum and could be more heavily focused on.

Conical flasks, stoppers and tubes may not be required for this activity if alternatives can be sourced, such as mini pop bottles and clean fromage frais pots.

Dissolve and precipitate activity sheet

Additional information.

This lesson plan was originally part of the  Assessment for Learning  website, published in 2008.

Assessment for Learning is an effective way of actively involving students in their learning.  Each session plan comes with suggestions about how to organise activities and worksheets that may be used with students.

Acknowledgements

V. Barker,  Beyond Appearances : Student’s misconceptions about basic chemical ideas: A report prepared for The Royal Society of Chemistry, London.  London: Royal Society of Chemistry, 2000.

• 11-14 years
• Practical experiments
• Formative assessment 
• Lesson planning
• Quantitative chemistry and stoichiometry
• Physical chemistry

Specification

• The law of conservation of mass states that no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants.
• Recall and use the law of conservation of mass.
• 1.47 Explain the law of conservation of mass applied to: a closed system including a precipitation reaction in a closed flask
• 1.47a Explain the law of conservation of mass applied to: a closed system including a precipitation reaction in a closed flask
• C5.3.1 recall and use the law of conservation of mass
• C5.2.1 recall and use the law of conservation of mass
• C1.3k recall and use the law of conservation of mass
• C1.3i recall and use the law of conservation of mass
• Many ionic compounds are soluble in water. As they dissolve the lattice structure breaks up allowing water molecules to surround the separated ions.
• (k) chemical reactions as a process of re-arrangement of the atoms present in the reactants to form one or more products, which have the same total number of each type of atom as the reactants
• 1.1 Atomic structure
• 1. Investigate whether mass is unchanged when chemical and physical changes take place.
• 2. Develop and use models to describe the nature of matter; demonstrate how they provide a simple way to to account for the conservation of mass, changes of state, physical change, chemical change, mixtures, and their separation.
• 4. Classify substances as elements, compounds, mixtures, metals, non-metals, solids, liquids, gases and solutions.

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2 Easy Examples of the Law of Conservation of Mass

General Education

Chemistry is an important subject that you’ll definitely need to know if you’re planning to pursue a chemistry or other science major in college. One thing you should be familiar with is the law of conservation of mass.  What is it? And how is it used in chemistry?

Keep reading to learn what the law of conservation of mass is and how it came to be. We will also give you some law of conservation of mass examples to help you understand the concept better.

What Is the Law of Conservation of Mass?

First off, exactly what is the law of conservation of mass? This law states that in a closed system, matter can neither be created nor destroyed—it can only change form.

Put differently, the amount, or mass, of matter in an isolated system will always be constant regardless of any chemical reactions or physical changes that take place. (Note that an isolated or closed system is one that does not interact with its environment.)

This law is important in chemistry, particularly when combining different materials and testing the reactions between them.

In chemistry, the law of conservation of mass states that  the mass of the products (the chemical substances created by a chemical reaction) will always equal the mass of the reactants (the substances that make the chemical reaction).

Think of it as being similar to balancing an algebraic equation. Both sides around an equal sign might look different (for example, 6 a + 2 b = 20), but they still represent the same total quantity. This is similar to how the mass must be constant for all matter in a closed system—even if that matter changes form!

But how does the law of conservation of mass work?

When a substance undergoes a chemical reaction, you might assume that some or even all of the matter present is disappearing, but, in actuality, it's simply changing form.

Think about when a liquid turns into a gas. You might think that the matter (in this case, the liquid) has simply vanished. But if you were to actually measure the gas, you'd find that the initial mass of the liquid hasn’t actually changed.  What this means is that the substance, which is now a gas, still has the same mass it had when it was a liquid (yes—gas has mass, too!).

What Is the History Behind the Law of Conservation of Mass?

Though many people, including the ancient Greeks, laid the scientific groundwork necessary for the discovery of the law of conservation of mass, it is French chemist Antoine Lavoisier (1743-1794) who is most often credited as its discoverer. This is also why the law is occasionally called Lavoisier’s law.

In the late 1700s, Lavoisier proved through experimentation that the total mass does not change in a chemical reaction, leading him to declare that matter is always conserved in a chemical reaction.

Lavoisier’s experiments marked the first time someone clearly tested this idea of the conservation of matter by measuring the masses of materials both before and after they underwent a chemical reaction.

Ultimately, the discovery of the law of conservation of mass was immensely significant to the field of chemistry because it proved that matter wasn’t simply disappearing (as it appeared to be) but was rather changing form into another substance of equal mass.

What Are Some Law of Conservation of Mass Examples?

Law of conservation of mass examples are useful for visualizing and understanding this crucial scientific concept. Here are two examples to help illustrate how this law works.

Example 1: The Bonfire/Campfire

One common example you’ll come across is the image of a bonfire or campfire.

Picture this: you’ve gathered some sticks with friends and lit them with a match. After a couple of toasted marshmallows and campfire songs, you realize that the bonfire, or campfire, you've built has completely burned down. All you’re left with is a small pile of ashes and some smoke.

Your initial instinct might be to assume that some of the campfire's original mass from the sticks has somehow vanished. But it actually hasn’t —i t’s simply transformed!

In this scenario, as the sticks burned, they combined with oxygen in the air to turn into not just ash but also carbon dioxide and water vapor. As a result, If we measured the total mass of the wooden sticks and the oxygen before setting the sticks on fire, we'd discover that this mass is equal to the mass of the ashes, carbon dioxide, and water vapor combined.

Example 2: The Burning Candle

A similar law of conservation of mass example is the image of a burning candle.

For this example, picture a regular candle, with wax and a wick. Once the candle completely burns down, though, you can see that there is definitely far less wax than there was before you lit it. This means that some of the wax (not all of it, as you’ve likely noticed with candles you’ve lit in real life!) has been transformed into gases —namely,  water vapor and carbon dioxide.

As the previous example with the bonfire has shown, no matter (and therefore no mass) is lost through the process of burning.

Recap: What Is the Law of Conservation of Mass?

The law of conservation of mass is a scientific law popularized and systematized by the 18th-century French chemist Antoine Lavoisier.

According to the law, in an isolated system, matter cannot be created or destroyed — only changed.  This means that the total mass of all substances before a chemical reaction will equal the total mass of all substances after a chemical reaction. Simply put, matter (and thus mass) is always conserved, even if a substance changes chemical or physical form.

Knowing this scientific law is important for the study of chemistry, so if you plan to get into this field, you'll definitely want to understand what the law of conservation of mass is all about!

What’s Next?

Are there other science topics you want to review? Then you're in luck! Our guides will teach you loads of useful topics, from how to convert Celsius to Fahrenheit , to what the density of water is , to how to balance chemical equations .

Need help identifying stylistic techniques in a book you're reading for English class? Let our comprehensive list of the most important literary devices lend you a hand!

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Hannah received her MA in Japanese Studies from the University of Michigan and holds a bachelor's degree from the University of Southern California. From 2013 to 2015, she taught English in Japan via the JET Program. She is passionate about education, writing, and travel.

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The Conservation of Matter During Physical and Chemical Changes

Matter makes up all visible objects in the universe, and it can be neither created nor destroyed.

Chemistry, Conservation, Earth Science, Geology, Physics

Water in Three States

Water can exist in three different physical states—as a gas, liquid, and a solid—under natural conditions on Earth. Regardless of its physical state, they all have the same chemical composition. Water is 2 hydrogen atoms bonded to 1 oxygen atom.

Photograph by OJO Images Ltd.

Matter makes up everything visible in the known universe, from porta-potties to supernovas . And because matter is never created or destroyed, it cycles through our world. Atoms that were in a dinosaur millions of years ago—and in a star billions of years before that—may be inside you today. Matter is anything that has mass and takes up space. It includes molecules , atoms, fundamental particles , and any substance that these particles make up. Matter can change form through physical and chemical changes, but through any of these changes matter is conserved . The same amount of matter exists before and after the change—none is created or destroyed. This concept is called the Law of Conservation of Mass . In a physical change, a substance’s physical properties may change, but its chemical makeup does not. Water, for example, is made up of two hydrogen atoms and one oxygen atom. Water is the only known substance on Earth that exists naturally in three states: solid, liquid, and gas. To change between these states, water must undergo physical changes. When water freezes, it becomes hard and less dense, but it is still chemically the same. There are the same number of water molecules present before and after the change, and water’s chemical properties remain constant. To form water, however, hydrogen and oxygen atoms must undergo chemical changes. For a chemical change to occur, atoms must either break bonds and/or form bonds. The addition or subtraction of atomic bonds changes the chemical properties of the substances involved. Both hydrogen and oxygen are diatomic —they exist naturally as bonded pairs (H 2 and O 2 , respectively). In the right conditions, and with enough energy, these diatomic bonds will break and the atoms will join to form H 2 O (water). Chemists write out this chemical reaction as:

2H 2 + O 2 → 2H 2 O

This equation says that it takes two molecules of hydrogen and one molecule of oxygen to form two molecules of water. Notice that there are the same number of hydrogen atoms and oxygen atoms on either side of the equation. In chemical changes, just as in physical changes, matter is conserved. The difference in this case is that the substances before and after the change have different physical and chemical properties. Hydrogen and oxygen are gases at standard temperature and pressure, whereas water is a colorless, odorless liquid. Ecosystems have many chemical and physical changes happening all at once, and matter is conserved in each and every one—no exceptions. Consider a stream flowing through a canyon—how many chemical and physical changes are happening at any given moment? First, let’s consider the water. For many canyon streams, the water comes from higher elevations and originates as snow. Of course that’s not where the water began —it’s been cycled all over the world since Earth first had water. But in the context of the canyon stream, it began in the mountains as snow. The snow must undergo a physical change —melting—to join the stream. As the liquid water flows through the canyon, it may evaporate (another physical change) into water vapor. Water gives a very clear example of how matter cycles through our world, frequently changing form but never disappearing. Next, consider the plants and algae living in and along the stream. In a process called photosynthesis , these organisms convert light energy from the sun into chemical energy stored in sugars. However, the light energy doesn’t produce the atoms that make up those sugars—that would break the Law of Conservation of Mass —it simply provides energy for a chemical change to occur. The atoms come from carbon dioxide in the air and water in the soil. Light energy allows these bonds to break and reform to produce sugar and oxygen, as shown in the chemical equation for photosynthesis :

6CO 2 + 6H 2 O + light → C 6 H 12 O 6 (sugar)+ 6O 2

This equation says that six carbon dioxide molecules combine with six water molecules to form one sugar molecule and six molecules of oxygen. If you added up all the carbon, hydrogen, and oxygen atoms on either side of the equation, the sums would be equal; matter is conserved in this chemical change. When animals in and around the stream eat these plants, their bodies use the stored chemical energy to power their cells and move around. They use the nutrients in their food to grow and repair their bodies—the atoms for new cells must come from somewhere. Any food that enters an animal’s body must either leave its body or become part of it; no atoms are destroyed or created. Matter is also conserved during physical and chemical changes in the rock cycle. As a stream carves deeper into a canyon, the rocks of the canyon floor don’t disappear. They’re eroded by the stream and carried off in small bits called sediments. These sediments may settle at the bottom of a lake or pond at the end of the stream, building up in layers over time. The weight of each additional layer compacts the layers beneath it, eventually adding so much pressure that new sedimentary rock forms. This is a physical change for the rock, but with the right conditions the rock may chemically change too. In either case, the matter in the rock is conserved. The bottom line is: Matter cycles through the universe in many different forms. In any physical or chemical change, matter doesn’t appear or disappear. Atoms created in the stars (a very, very long time ago) make up every living and nonliving thing on Earth—even you. It’s impossible to know how far and through what forms your atoms traveled to make you. And it’s impossible to know where they will end up next. This isn’t the whole story of matter, however, it’s the story of visible matter. Scientists have learned that about 25 percent of the universe’s mass consists of dark matter—matter that cannot be seen but can be detected through its gravitational effects. The exact nature of dark matter has yet to be determined. Another 70 percent of the universe is an even more mysterious component called dark energy, which acts counter to gravity. So “normal” matter makes up, at most, five percent of the universe.

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New results from the CMS experiment put W boson mass mystery to rest

September 17, 2024

Media contact

• Tracy Marc, Fermilab, [email protected] , 224-290-7803

After an unexpected measurement by the Collider Detector at Fermilab (CDF) experiment in 2022, physicists on the Compact Muon Solenoid experiment at the Large Hadron Collider  announced today a new mass measurement of the W boson , one of nature’s force-carrying particles. This new measurement, which is a first for the CMS experiment, uses a new technique that makes it the most elaborate investigation of the W boson’s mass to date. Following nearly a decade of analysis, CMS has found that the W boson’s mass is consistent with predictions, finally putting a multi-year long mystery to rest. View the paper .

The Compact Muon Solenoid detector is located 100 meters underground on the Franco-Swiss borderer at CERN and collects data from the Large Hadron Collider. The detector has been operational since 2010 and is used by one of largest international scientific collaborations in history to study the fundamental laws of nature. Photo: Brice, Maximilien: CERN

The final analysis used 300 million events collected from the 2016 run of the LHC, and 4 billion simulated events. From this dataset, the team reconstructed and then measured the mass from more than 100 million W bosons. They found that the W boson’s mass is 80 360.2 ± 9.9 megaelectron volts (MeV), which is consistent with the Standard Model’s predictions of 80 357 ± 6 MeV. They also ran a separate analysis that cross-checks the theoretical assumptions.

“The new CMS result is unique because of its precision and the way we determined the uncertainties,” said Patty McBride, a distinguished scientist at the U.S. Department of Energy’s Fermi National Research Laboratory and the former CMS spokesperson. “We’ve learned a lot from CDF and the other experiments who have worked on the W boson mass question. We are standing on their shoulders, and this is one of the reasons why we are able to take this study a big step forward.”

Since the W boson was discovered in 1983, physicists on 10 different experiments have measured its mass.

The W boson is one of the cornerstones of the Standard Model , the theoretical framework that describes nature at its most fundamental level. A precise understanding of the W boson’s mass allows scientists to map the interplay of particles and forces, including the strength of the Higgs field and merger of electromagnetism with the weak force, which is responsible for radioactive decay.

“The entire universe is a delicate balancing act,” said Anadi Canepa, deputy spokesperson of the CMS experiment and a senior scientist at Fermilab. “If the W mass is different from what we expect, there could be new particles or forces at play.”

Comparison measurements of the W boson’s mass with other experiments and the Standard Model prediction. The dot is the measured value and length of the line corresponds to the precision; the shorter the line, the more precise the measurement. Image based on a figure produced by the CMS collaboration. Created by Samantha Koch, Fermilab

The new CMS measurement has a precision of 0.01%. This level of precision corresponds to measuring a 4-inch-long pencil to between 3.9996 and 4.0004 inches. But unlike pencils, the W boson is a fundamental particle with no physical volume and a mass that is less than a single atom of silver.

“This measurement is extremely difficult to make,” Canepa added. “We need multiple measurements from multiple experiments to cross-check the value.”

The CMS experiment is unique from the other experiments that have made this measurement because of its compact design, specialized sensors for fundamental particles called muons and an extremely strong solenoid magnet that bends the trajectories of charged particles as they move through the detector.

“CMS’s design makes it particularly well-suited for precision mass measurements,” McBride said. “It’s a next generation experiment.”

Because most fundamental particles are incredibly short-lived, scientists measure their masses by adding up the masses and momenta of everything they decay into. This method works well for particles like the Z boson, a cousin of the W boson, which decays into two muons. But the W boson poses a big challenge because one of its decay products is a tiny fundamental particle called a neutrino.

“Neutrinos are notoriously difficult to measure,” said Josh Bendavid, a scientist at the Massachusetts Institute of Technology who worked on this analysis. “In collider experiments, the neutrino goes undetected, so we can only work with half the picture.”

Working with just half the picture means that the physicists need to be creative. Before running the analysis on real experimental data, the scientists first simulated billions of LHC collisions.

“In some cases, we even had to model small deformations in the detector,” Bendavid said. “The precision is high enough that we care about small twists and bends; even if they’re as small as the width of a human hair.”

Physicists also need numerous theoretical inputs, such as what is happening inside the protons when they collide, how the W boson is produced, and how it moves before it decays.

“It’s a real art to figure out the impact of theory inputs,” McBride said.

In the past, physicists used the Z boson as a stand-in for the W boson while calibrating their theoretical models. While this method has many advantages, it also adds a layer of uncertainty into the process.

“Z and W bosons are siblings, but not twins,” said Elisabetta Manca, a researcher at the University of California Los Angeles and one of the analyzers. “Physicists need to make a few assumptions when extrapolating from the Z to the W, and these assumptions are still under discussion.”

To reduce this uncertainty, CMS researchers developed a novel analysis technique that uses only real W boson data to constrain the theoretical inputs.

Anadi Canepa, deputy spokesperson of the CMS experiment and a senior scientist at Fermilab, and Patty McBride, a distinguished scientist at Fermilab and the former CMS spokesperson, are leaders within the CMS collaboration and have worked closely with the analysis team since 2022. Photo: Saskia Theresa Rodriguez, CERN

“We were able to do this effectively thanks to a combination of a larger data set, the experience we gained from an earlier W boson study, and the latest theoretical developments,” Bendavid said. “This has allowed us to free ourselves from the Z boson as our reference point.”

As part of this analysis, they also examined 100 million tracks from the decays of well-known particles to recalibrate a massive section of the CMS detector until it was an order of magnitude more precise.

“This new level of precision will allow us to tackle critical measurements, such as those involving the W, Z and Higgs bosons, with enhanced accuracy,” Manca said.

The most challenging part of the analysis was its time intensiveness, since it required creating a novel analysis technique and developing an incredibly deep understanding of the CMS detector.

“I started this research as a summer student, and now I’m in my third year as a postdoc,” Manca said. “It’s a marathon, not a sprint.”

  The Compact Muon Solenoid (CMS) experiment is funded in part by the Department of Energy’s Office of Science and the National Science Foundation. It is one of two large general-purpose experiments at the  Large Hadron Collider (LHC) at  CERN , the European Particle Physics Laboratory. 

  Fermilab is the host laboratory in the U.S. that facilitates the participation of hundreds of USCMS physicists from more than 50 university groups and plays a leading role in detector construction and operations, computing and software, and data analysis.

  Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit  science.energy.gov .