Chapter 5- Atomic Structure

Isotopes

Atoms of the same element with the same number of electrons and protons but different number of neutrons.

Atoms

________ lose or gain electrons to become either positive ions (cations) or negative ions (anions)

Protons

Sub-atomic particles with a positive charge.

equal number of protons

Since an atom has a(n) ________ and electrons, it is neutral (no charge)

Electrons

Sub-atomic particles with a negative charge.

Proton number

Number of protons (and therefore electrons) in an atom.

Sub-atomic particles

A particle that composes an atom.

Mass Number

Number of protons and neutrons in an atom.

Electronic configuration

The distribution of electrons of an atom or molecule in atomic or molecular orbitals.

Valence electrons.

The electrons in the last shell of an atom.

Ions

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.