Chemical Reactions

Front

What is a molecule?

Back

A molecule is made of more than one atom.

Front

If you start a chemical reaction with 5 atoms of helium, how many atoms will you have after?

Back

You will still have 5 atoms.

Front

What are some signs that a chemical reaction has occurred?

Back

Signs include color change, odor change, and properties change.

Front

What is a catalyst?

Back

A catalyst is a substance that helps a chemical reaction happen faster.

Front

What results in no new substances?

Back

A physical change results in no new substances.

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change.

Front

What is an example of a chemical change?

Back

Burning wood is an example of a chemical change.

Front

What is a reactant?

Back

A reactant is a substance that starts a chemical reaction.