Elements, Compounds, and Reactions

Front

What is an element?

Back

The simplest form of matter.

Front

What are the main elements found in the human body?

Back

Carbon, hydrogen, oxygen, sulfur, nitrogen, phosphorus, and about a dozen other elements.

Front

What is an atom?

Back

The smallest particle of an element that keeps the chemical identity of the element.

Front

How are carbon atoms different from hydrogen and oxygen atoms?

Back

Each element has a unique type of atom; carbon atoms are different from hydrogen and oxygen atoms.

Front

What is a compound?

Back

A substance that contains two or more different elements that are chemically joined.

Front

Give an example of a compound.

Back

Water, which is made from hydrogen and oxygen.

Front

What is a molecule?

Back

A group of two or more atoms joined together chemically.

Front

What is a mixture?

Back

A combination of different elements and compounds that are not chemically joined together.

Front

What is a chemical reaction?

Back

A process that rearranges the atoms of one or more substances into one or more new substances.

Front

What happens when hydrogen reacts with oxygen?

Back

It produces water and energy.