HS-PS1-7: Mass is conserved in chemical reactions

HS-PS1-7:  Use mathematical representations to support the claim that atoms, and therefore mass,  are conserved during a chemical reaction.

 PS1-7 Evidence Statements

The video below discusses the decomposition reaction of hydrogen peroxide and uses a balanced chemical equation and structural formulas to explain why the number of atoms is conserved in a chemical reaction.


An experiment to help teach the concept of conservation of mass can be found here.

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