Law of conservation of mass

Front

What does the Law of Conservation of Mass state?

Back

Matter cannot be created nor destroyed; it can only be rearranged or changed.

Front

What are reactants in a chemical reaction?

Back

Substances that undergo change during a chemical reaction.

Front

What are products in a chemical reaction?

Back

Substances that are formed as a result of a chemical reaction.

Front

What is a balanced chemical equation?

Back

An equation where both sides have the same number of atoms of each element.

Front

What is a subscript in a chemical formula?

Back

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

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

If a reaction starts with 20g of reactants, how much mass will the products have?

Back

20g of products, according to the Law of Conservation of Mass.

Front

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

Back

The mass remains constant; it is conserved.

Front

What is an example of a chemical reaction?

Back

Combining hydrogen and oxygen to form water (2H2 + O2 -> 2H2O).

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.