Elements, Compounds, Chemical Changes, and Counting Atoms

Front

What is a characteristic of a physical change?

Back

The original substance can often be recovered.

Front

What do we call two or more atoms chemically bonded together?

Back

Molecule

Front

How many Hydrogen atoms are in 4H₂O?

Back

8

Front

Are there any compounds on the periodic table?

Back

No, because only elements are on the periodic table.

Front

What does a subscript indicate in a chemical formula?

Back

The number of atoms of that element.

Front

What is an element?

Back

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

Front

What is a compound?

Back

A substance formed when two or more elements are chemically bonded together.

Front

What is a chemical change?

Back

A change that results in the formation of new chemical substances.

Front

What is the law of conservation of mass?

Back

Mass is neither created nor destroyed in a chemical reaction.

Front

What is a mixture?

Back

A combination of two or more substances that are not chemically bonded.