Atomic Structure

Electron

Mass: - 1/1840 A.M.U

Charge: - -1

Nucleus

Proton

Charge: - +1

Mass: - 1 A.M.U

Neutron

Charge: - 0

Mass: - 1 A.M.U.

Are formed when atoms gain or lose electrons

Are charged particles

Positive: - Cations

Lost electrons

Negative: - Anions

Gained electrons

Atoms of the same element with different atomic mass

Due to differing numbers of neutrons

The number of protons or electrons in an atom

The number of protons + the number of neutrons