Atoms & Molecules

The basic building block for matter. Makes up elements.

• atom

• nucleus

• molecule

• isotope

The small core of the atom; contains neutrons and protons

• electron

• atom

• nucleus

• element

A part of the nucleus; has a positive charge and mass of 1 amu.

• neutron

• proton

• electron

• nucleus

Part of the nucleus; has no charge, and a mass of 1 amu.

• nucleus

• proton

• neutron

• electron

Moves around the nucleus; has a negative charge and mass of 1/2000 amu.

• neutron

• electron

• proton

• isotope

Is made up of a single type of atom. It is identified by the number of protons in the nucleus. A pure substance that cannot be broken down into other substances.

• molecule

• isotope

• atom

• element

A group of two or more atoms held together by chemical bonds.

• mixture

• compound

• molecule

• element

A substance made of two or more elements chemically combined in a set ratio. Example:  $H_2O,\ CH_4$  

• compound

• mixture

• molecule

• isotope

Two or more substances that are together, but NOT chemically combined.

• element

• molecule

• compound

• mixture

Substances that are evenly mixed so that you cannot see the different parts.

• homogeneous mixture

• compound

• molecule

• heterogeneous mixture