Protons, Neutrons, and electrons

Subatomic Particles

The nucleus

Almost all the mass of the atom Radius is 1/10,000 the size of the radius of the atom

Atoms are electrically neutral because:

# of protons = # of electrons (e^-) if electorally neutral

Isotopes

Same #p, different #n

They are the same element because same Z

different masses because different #n

Mass Number (A)

#p+#n=A

z + n=A

Ions

Charged particles formed when atom's gain or lose electrons

Cation

Positively charged ion

Anion

Negatively charged ion

Atomic mass =

fraction of isotope * mass of isotope

Artifical elements

Z > 92

Artificial elements do not have:

Atomic masses because thy have no naturally occurring isotopes

Elements within the same row:

are in the same period

Elements within the same column:

Similar chemical properties