Notes on Subatomic Particles
There are 3 subatomic particles in an
atom:
1. proton
2. neutron
3. electron
nucleus
Electrons
Proton
(positive)
Neutron
(neutral)
(negative)
Subatomic
Particle
Proton
(p+)
Neutron
(n)
Charge
positive
nucleus
neutral
nucleus
Mass
1 amu
(atomic mass unit)
1 amu
Zip around
Electron
(e-)
Location
negative
nucleus in
shells
_1_
1837
amu
When using the periodic table to find
subatomic particle information…
Atomic mass # A
symbol
Atomic #
Atomic mass # :
Atomic # :
Z
•Is a number in decimal form
•When you round it, it tells you
the mass of p+ + n + e
x•Tells the # of p+
•Tells the # of e-
To find the # of neutrons:
Atomic mass # - atomic #
=
# neutrons
Atoms that aren’t typical

ISOTOPE – atom with a number of
neutrons that is higher or lower than
what’s indicated on the periodic table
(typically radioactive)

ION – atom with a number of
electrons that is higher (anion) or
lower (cation) than what’s indicated on
the periodic table
Examples on Subatomic Particle
Worksheet:
symbol
name
23
sodium
11 Na
91
40 Zr zirconium
133
55 Cs
cesium
Z
11
p+
11
n
A
e-
12
23
11
40
40
51
91
40
55
55
78
133
55
Notes on the Periodic Table

Periodic table created by Dimitri Mendeleev
He organized it by increasing mass
(doesn’t work…look at #27 and #28)
and by similar properties
NOW
organized by increasing
atomic number and by similar
properties
Organization of the Periodic Table
Rows () – periods, shells, energy levels,
electron clouds
Columns (↕) – groups, families, # of valence
electrons
Left of Zig Zag Line - metals, cations (positive ions)
Zig Zag Line – metalloids, semi-metals, semiconductors
Right of ZigZag Line – non-metals, anions (negative ions)
Families of the Periodic
Table
Column 1 – Alkali Metals
Column 2 – Alkaline Earth Metals

8 (18) – Nobel Gases
Column 7 (17) – Halogens
Column 6 (16) – Oxygen Family
Column
* Column 5 (15) – Nitrogen Family
**Note: Only Down to Zig Zag line for Oxygen Family and Nitrogen Family!!
Families of the Periodic
Table continued…
Middle of the periodic table …
TRANSITION METALS
Coinage
Family (Cu, Ag, Au)
Lanthanides
Actinides
(1st row on bottom)
(2nd row on bottom)