Chemical Reactions

Front

What is a chemical reaction?

Back

A process where reactants break apart, rearrange, and combine in new ways to form products.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Front

What are reactants in a chemical reaction?

Back

The starting substances that undergo change during a chemical reaction.

Front

What are products in a chemical reaction?

Back

The new substances formed as a result of a chemical reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Front

What does the chemical formula CH4 represent?

Back

Methane, a molecule consisting of one carbon atom and four hydrogen atoms.

Tags

NGSS.MS-PS1-1

Front

What happens to atoms during a chemical reaction?

Back

Atoms are rearranged to form new substances, but they are not created or destroyed.

Tags

NGSS.MS-PS1-5

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.

Tags

NGSS.MS-PS1-5

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 in the reaction.

Tags

NGSS.MS-PS1-5

Front

What is a subscript in a chemical formula?

Back

A small number written after an element symbol that indicates the number of atoms of that element in a molecule.

Front

How do you determine the number of atoms in a molecule from its formula?

Back

Count the number of atoms indicated by the subscripts in the formula.

Tags

NGSS.MS-PS1-1

Front

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

Back

A chemical change results in the formation of new substances, while a physical change does not change the substance's chemical identity.

Tags

NGSS.MS-PS1-2