Unit Two

Atom

Nucleus

Determines if an element
is an isotope or not

Is an isotope if the mass of protons and neutrons are the same. Also is a proton if protons are the same and neutrons are not.

It is NOT an isotope if the protons,
ALONE, are not the same.

Neutrons

Mass-Protons

A

Atomic Number

Electrons

Valence Electrons

Outer layer of electron cloud

Can be determined by the
elements placement on
the Periodic Table

Electron Cloud

Contains ONLY the electrons, ever

Neutral Charge
(0)

Positive Charge
(+1)

Negative Charge
(-1)

Equals the number of Protons
if it is NEUTRAL

Added toghether
equals the mass
number

Floating topic