Atoms and Molecules

Front

What is an atom?

Back

The smallest unit of matter that retains the properties of an element.

Front

What is a molecule?

Back

A group of two or more atoms bonded together.

Front

How many atoms are in a molecule of ammonia (NH3)?

Back

Four (1 nitrogen atom and 3 hydrogen atoms).

Front

What is the chemical formula for carbon dioxide?

Back

CO2.

Front

How many oxygen atoms are in carbon dioxide (CO2)?

Back

Two.

Front

Is CO2 an element?

Back

No, it is a compound made of carbon and oxygen.

Front

What is an element?

Back

A pure substance that cannot be broken down into simpler substances by chemical means.

Front

Is helium (He) an element?

Back

Yes, helium is a chemical element.

Front

What is the difference between an atom and a molecule?

Back

An atom is a single unit of an element, while a molecule is made up of two or more atoms bonded together.

Front

What do we call a substance made of only one type of atom?

Back

An element.