--- title: 2 Easy Examples of the Law of Conservation of Mass · PrepScholar description: What is the law of conservation of mass? We explain this important physics law and walk you through helpful examples of how it works. image: https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/feature_chemist_lab.jpg --- **[![PrepScholar](https://www.prepscholar.com/wp-content/uploads/2023/03/PrepScholar-Logo-Colored.png)](https://www.prepscholar.com/)** CALL NOW: [+1 (866) 811-5546](tel:18668115546) [![Start Free Trial](https://no-cache.hubspot.com/cta/default/360031/interactive-171805697634.png)](https://cta-service-cms2.hubspot.com/web-interactives/public/v1/track/redirect?encryptedPayload=AVxigLKJluK2NyG3jpAJh%2F2lClc1fhnVHyMZoQonqRxtJngB8FMX6lc78F84JqOaVAL0d36TA5%2FYuH%2FLCJw8AG3ewREi%2F7a3XDouZgjxWfYCBUge6z76KnSykOxONl3avMK0gUjJGpJdyJE2BDTx8g3bsgHwMtx4Kr9Jfh6Jr7WA2XEIgtLw1OoVvAMo4Kw%3D&webInteractiveContentId=171805697634&portalId=360031) ## Choose Your Test SAT Prep ACT Prep [PrepScholar Advice Blog](https://blog.prepscholar.com/) ☰ - Search Blogs By Category - [SAT](https://blog.prepscholar.com/topic/sat) - [ACT](https://blog.prepscholar.com/topic/act) - [College Admissions](https://blog.prepscholar.com/topic/college-admissions) - [AP and IB Exams](https://blog.prepscholar.com/topic/advanced-placement-ap) - [PSAT](https://blog.prepscholar.com/topic/psat-info-and-strategies) - [TOEFL](https://blog.prepscholar.com/topic/toefl) - [GPA and Coursework](https://blog.prepscholar.com/topic/coursework-gpa) # [2 Easy Examples of the Law of Conservation of Mass](https://blog.prepscholar.com/what-is-the-law-of-conservation-of-mass-examples) ![author image](https://cdn2.hubspot.net/hubfs/360031/author_hannah.png) Posted by [Hannah Muniz](https://blog.prepscholar.com/author/hannah-muniz) | Updated on September 24, 2024 [General Education](https://blog.prepscholar.com/topic/general-education)   ![feature_chemist_lab](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/feature_chemist_lab.jpg?width=500&name=feature_chemist_lab.jpg) 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.   ![body_Antoine_Lavoisier](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/body_Antoine_Lavoisier.jpg?width=247&name=body_Antoine_Lavoisier.jpg)*Lavoisier lookin' proud of his discovery.*   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.   ![body_bonfire](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/body_bonfire.png?width=252&name=body_bonfire.png)   ### 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—it’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.**   ![body_burning_candle](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/body_burning_candle.png?width=275&name=body_burning_candle.png)   ### 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](https://blog.prepscholar.com/convert-celsius-to-fahrenheit), to [what the density of water is](https://blog.prepscholar.com/what-is-the-density-of-water), to [how to balance chemical equations](https://blog.prepscholar.com/balancing-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](https://blog.prepscholar.com/list-of-literary-devices-techniques) lend you a hand!   [![Looking for help with high school? Our one-on-one online tutoring services can help you study for important exams, review challenging material, or plan out big projects. Get matched with a top tutor who is an expert in the subject you're studying!](https://no-cache.hubspot.com/cta/default/360031/interactive-178532613026.png)](https://blog.prepscholar.com/hs/cta/wi/redirect?encryptedPayload=AVxigLJxi6R%2F1HjABbAkV%2BnIoCxmjQVFRqEzkxdPt7lCFuSOs7eQcv6wL2iyCUZQDgcEUQysa7KkqSlylVitn4gKQNRKQw0ZuXpZrug7XSbnoNcM463dIqolsVudleytFrv5Hbxuia8Ln14aPq6mlFsC4EUSwB2SRk%2BVWadlsgdIW8ojm%2B%2BsENgI2PVr1Q6KfSKHyZE%3D&webInteractiveContentId=178532613026&portalId=360031) ### Trending Now [How to Get Into Harvard and the Ivy League](https://blog.prepscholar.com/how-to-get-into-harvard-and-the-ivy-league-by-a-harvard-alum) [How to Get a Perfect 4.0 GPA](https://blog.prepscholar.com/how-to-get-a-4-0-gpa-and-get-better-grades-by-a-harvard-alum) [How to Write an Amazing College Essay](https://blog.prepscholar.com/how-to-write-a-college-essay) [Should You Take the SAT or ACT?](https://quiz.prepscholar.com/sat-vs-act) [What Exactly Are Colleges Looking For?](https://blog.prepscholar.com/what-do-colleges-look-for) [ACT vs. SAT: 10 Key Differences](https://blog.prepscholar.com/act-vs-sat) [Calculate Your College Chances](https://mycollegechances.prepscholar.com/) Get Your Free **[![PrepScholar](https://www.prepscholar.com/wp-content/uploads/2023/03/PrepScholar-Logo-Colored.png)](https://www.prepscholar.com/)** eBook [5 Tips to Raise Your SAT Score 160+ Points](https://www.prepscholar.com/rp/sat-5-tips-ebook/) [5 Tips to Raise Your ACT Score 4+ Points](https://www.prepscholar.com/rp/act-5-tips-ebook/) ### SAT Prep [Find Your Target SAT Score](https://blog.prepscholar.com/what-is-a-good-sat-score-a-bad-sat-score-an-excellent-sat-score) [Free Complete Official SAT Practice Tests](https://blog.prepscholar.com/complete-official-sat-practice-tests-free-links) ### **[How to Get a Perfect SAT Score, by an Expert Full Scorer](https://blog.prepscholar.com/how-to-get-a-perfect-sat-score-by-a-2400-sat-scorer)** [Score 800 on SAT Math](https://blog.prepscholar.com/how-to-get-800-on-sat-math-by-a-perfect-scorer) [Score 800 on SAT Reading and Writing](https://blog.prepscholar.com/how-to-get-800-on-sat-reading-and-writing) [Raise Your SAT Score by 160+ Points GUARANTEED. Start Your 5-Day Risk-Free Trial](https://www.prepscholar.com/sat-test-prep/?utm_source=databasepage&utm_medium=sidebar&utm_campaign=sat_guarantee) ### ACT Prep [Find Your Target ACT Score](https://blog.prepscholar.com/what-is-a-good-act-score-a-bad-act-score-an-excellent-act-score) [Complete Official Free ACT Practice Tests](https://blog.prepscholar.com/complete-official-act-practice-tests-free-links) ### **[How to Get a Perfect ACT Score, by a 36 Full Scorer](https://blog.prepscholar.com/how-to-get-a-perfect-act-score-by-a-36-full-scorer)** [Get a 36 on ACT English](https://blog.prepscholar.com/how-to-get-36-on-act-english-9-strategies-from-a-perfect-scorer) [Get a 36 on ACT Math](https://blog.prepscholar.com/how-to-get-36-on-act-math-8-strategies-by-a-perfect-scorer) [Get a 36 on ACT Reading](https://blog.prepscholar.com/how-to-get-36-on-act-reading-11-strategies-from-a-perfect-scorer) Stay Informed Get the latest articles and test prep tips! - [![Follow us on Facebook (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/facebook_logo.png)](https://www.facebook.com/prepscholar) - [![Follow us on X (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/twitterx-50.png)](https://twitter.com/intent/follow?region=follow_link&screen_name=PrepScholar&tw_p=followbutton) - [![Follow us on Instagram (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/instagram-sidebar.webp)](https://www.instagram.com/prepscholar/) Get Exclusive Tips for College Admissions Sign up to receive free guidance on everything from acing the SAT to writing a standout college admissions essay. × ## Thanks for Subscribing! ![Check icon](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/file-2386656898.png/subscribe_check.png.png?width=175&name=subscribe_check.png) To receive immediate updates on all our helpful guides and strategies, **follow us** on social media: [![Facebook](https://blogprepschola.wpenginepowered.com/wp-content/uploads/2025/03/26de6c2beb2b71ee5b8d660200359259.png)](https://www.facebook.com/prepscholar) [![X](https://blogprepschola.wpenginepowered.com/wp-content/uploads/2025/03/f233666501ea25d3fcf3c390d2f08c7b.png)](https://x.com/intent/follow?region=follow_link&screen_name=PrepScholar&tw_p=followbutton) [![LinkedIn](https://blogprepschola.wpenginepowered.com/wp-content/uploads/2025/03/linkedin.png)](https://www.linkedin.com/company/prepscholar/) [![Instagram](https://blogprepschola.wpenginepowered.com/wp-content/uploads/2025/03/download-1.png)](https://www.instagram.com/prepscholar/) **Have friends who also need help with test prep?** Share this article! [![Share on email](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/email-color.png?width=24&name=email-color.png)](mailto:?subject=Check%20out%20https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Demail%20&body=Check%20out%20https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Demail) [![Share on facebook](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/facebook-color.png?width=24&name=facebook-color.png)](http://www.facebook.com/share.php?u=https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Dfacebook) [![Share on twitter](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/x-twitter-color.png?width=24&name=x-twitter-color.png)](https://twitter.com/intent/tweet?original_referer=https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Dtwitter&url=https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Dtwitter&source=tweetbutton&text=) [![Share on linkedin](https://360031.fs1.hubspotusercontent-na1.net/hub/360031/hubfs/linkedin-color.png?width=24&name=linkedin-color.png)](http://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fblog.prepscholar.com%2Fwhat-is-the-law-of-conservation-of-mass-examples%3Futm_medium%3Dsocial%26utm_source%3Dlinkedin) About the Author ![author image](https://cdn2.hubspot.net/hubfs/360031/author_hannah.png) Hannah Muniz 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. ## Ask a Question Below Have any questions about this article or other topics? Ask below and we'll reply! **[![PrepScholar](https://www.prepscholar.com/wp-content/uploads/2023/03/PrepScholar-Logo-White.png)](https://www.prepscholar.com)** - [WHO WE ARE](https://www.prepscholar.com/who-we-are/) - [SUCCESS STORIES](https://www.prepscholar.com/case-studies/) - [ADVICE BLOG](https://blog.prepscholar.com/) - [FOR SCHOOLS](https://www.prepscholar.com/for-schools/) - [SAT](https://www.prepscholar.com/sat-test-prep/) - [ACT](https://www.prepscholar.com/act-test-prep/) - [PSAT](https://www.prepscholar.com/psat-test-prep/) - [AP](https://www.prepscholar.com/ap-tutoring/) - [GRE](https://www.prepscholar.com/gre-test-prep/) - [GMAT](https://www.prepscholar.com/gmat-test-prep/) - [TOEFL](https://www.prepscholar.com/toefl-test-prep/) - [ADMISSIONS](https://www.prepscholar.com/college-admissions-consulting/) - [TERMS OF SERVICE](https://www.prepscholar.com/terms-of-service/) - [PRIVACY POLICY](https://www.prepscholar.com/privacy-policy/) - [![follow us on X (icon)](https://cdn2.hubspot.net/hubfs/360031/twitter-64.png)](https://twitter.com/intent/follow?region=follow_link&screen_name=PrepScholar&tw_p=followbutton) - [![Follow us on Facebook (icon)](https://cdn2.hubspot.net/hubfs/360031/facebook-64.png)](https://www.facebook.com/prepscholar) - [![follow us on Instagram (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/instagram-64.svg)](https://www.instagram.com/prepscholar/) - [![follow us on TikTok (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/tiktok-50.svg)](https://www.tiktok.com/@prepscholarofficial) - [![Follow us on LinkedIn (icon)](https://360031.fs1.hubspotusercontent-na1.net/hubfs/360031/linkedin50.png)](https://www.linkedin.com/company/prepscholar/) © PrepScholar 2013-2025. All rights reserved SAT® is a registered trademark of the College Entrance Examination BoardTM. The College Entrance Examination BoardTM does not endorse, nor is it affiliated in any way with the owner or any content of this web site. ACT® is a registered trademark belonging to ACT Education Corporation ("ACT"). ACT is not involved with or affiliated with PrepScholar Inc., nor does ACT endorse or sponsor any of the products or services offered by PrepScholar Inc. GRE® and TOEFL® are registered trademarks of the ETS®. The ETS® does not endorse, nor is it affiliated in any way with, the owner or any content of this web site. GMAT® is a registered trademark of the Graduate Management Admissions Council®. The Graduate Management Admissions Council® does not endorse, nor is it affiliated in any way with, the owner or any content of this website. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Hannah Muniz", "url" : "https://blog.prepscholar.com/author/hannah-muniz" }, "dateModified" : "2024-09-24T16:45:47+00:00", "datePublished" : "2019-06-10T16:00:00+00:00", "description" : "What is the law of conservation of mass? We explain this important physics law and walk you through helpful examples of how it works.", "headline" : "2 Easy Examples of the Law of Conservation of Mass", "image" : "https://cdn2.hubspot.net/hubfs/360031/feature_chemist_lab.jpg", "mainEntityOfPage" : { "@id" : "https://blog.prepscholar.com/what-is-the-law-of-conservation-of-mass-examples", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://www.prepscholar.com/wp-content/uploads/2023/03/PrepScholar-Logo-Colored.png" }, "name" : "PrepScholar" } } ```