Law of Conservation of Mass

Front

What is the Law of Conservation of Mass?

Back

Mass is never created or destroyed in a chemical reaction.

Front

How many atoms are in the chemical formula H₂O?

Back

3 atoms (2 Hydrogen + 1 Oxygen).

Front

What does it mean when we say matter can be transformed?

Back

Matter can change forms or states but the total mass remains constant.

Front

What is a subscript in a chemical formula?

Back

A number written below and to the right of an element symbol indicating the number of atoms of that element.

Front

How many Calcium (Ca) atoms are in Ca(OH)₂?

Back

1 atom.

Front

What is a coefficient in a chemical equation?

Back

A number placed in front of a chemical formula to indicate how many molecules are involved.

Front

What happens to the mass of reactants in a chemical reaction?

Back

The total mass of the reactants equals the total mass of the products.

Front

What is an example of a physical change?

Back

Melting ice; the mass remains the same before and after the change.

Front

What is an example of a chemical change?

Back

Burning wood; new substances are formed and mass is conserved.

Front

What does it mean for a chemical reaction to be balanced?

Back

The number of atoms for each element is the same on both sides of the equation.