Ch 19 Physical Science Test

Front

A chemical reaction is:

Back

a process where substances are transformed into new substances

Front

Reactants are:

Back

substances that are present before a chemical reaction and take part in it

Front

Products

Back

substances after a reaction

Front

Who established that the total mass of the reactants always equals the total mass of the products, known as the Law of Conservation of Matter?

Back

Lavoisier

Front

What is a chemical equation?

Back

A representation of a chemical reaction using symbols and formulas

Front

A coefficient is:

Back

a number before a substance

Front

Why can you only add coefficients and not change subscripts in chemical equations?

Back

Coefficients change the number of molecules, while subscripts change the identity of the substance.

Front

What is a balanced chemical equation?

Back

An equation where the number of atoms of each element is equal on both sides.

Front

A mole is:

Back

a unit of amount of substance

Front

Molar mass

Back

the mass of one mole of a substance