# The law of conservation of mass - Todd Ramsey

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TEDEd Animation

## Let’s Begin…

Everything in our universe has mass — from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow while maintaining its mass? Todd Ramsey answers that question by unravelling the law of conservation of mass.

## Additional Resources for you to Explore

French scientist and aristocrat Antoine Lavoisier developed the Law of Conservation of Mass. Lavoisier is considered by many to be the father of chemistry bringing an end to the study of alchemy. This video clip from the BBC: Einstein’s Big Idea explains Lavoisier’s experiments! Watch this Crash Course video to learn more about how he developed this law, his other contributions to science, and how his work led to the discoveries of others. Lavoisier was amazing, wasn’t he?

Over time, the Law of Conservation of Mass allowed scientists to make calculations determining the necessary amounts of reactants to form a desired amount of products. Performing these calculations is known as stoichiometry. Watch this Hank Green Crash Course on Stoichiometry for more! Part of this process is balancing chemical equations to be sure the reaction obeys the Law of Conservation of Mass. The yields symbol (the arrow) in between the reactants and the products of a chemical equation acts just like an equals sign. The amount of each kind of atom on each side of the equation must be the same. When balancing equations, you can change numbers in front of compounds and molecules known as coefficients. These numbers tell you how many of each type of compound or molecule is involved in the reaction. Changing any other number in the formula changes the chemical makeup. This online simulation from the University of Colorado Boulder provides an interactive way to manipulate the atoms of an equation while still obeying the law. Give it a try and see if you can balance some chemical equations. Make a game of it!

If you’re curious about those early elements of the universe, check out these TED-Ed lessons on Hydrogen and Helium to learn about the chemical and physical properties of these critical and fundamental elements.

Interested in Carl Sagan and his “star stuff?” Watch this quick video from the American Chemical Society on exactly what Mr. Sagan meant when he said we were made up of the remains of stars. Then listen to Neil deGrasse Tyson poetically describe our connection to the stars. Prepare to be inspired.

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## Meet The Creators

• Educator Todd Ramsey
• Director Agota Vegso
• Animator Zsuzsanna Banyai
• Composer Dan O'Connor