Periodic Table Trends
Periods  Rows
(There are 7!)
Families/Groups
Columns
Have similar
chemical and
physical properties
Metals (Outlined in Black from left to right)
Most elements
are metals that
conduct heat
and electricity
quite well
With the
exception of Hg
(Mercury) they
all are solid at
room temp.
Gallium will melt
in your hand!
Most are
malleable (able
to be hammered
into sheets)
Most are Ductile
 able to be
pulled into wire
**Gold (Au) is soft and is mixed with other metals such as
copper and zinc to create an alloy for jewelry 
**White gold is comprised of “yellow “ gold and a whiter
metal, such as Rhodium
Non-Metals (Dark Blue Elements on
the Right Plus Hydrogen)
Most are
gasses, others
are brittle
solids. Bromine
is a liquid at
room
temperature.
Poor
conductors of
electricity
Carbon and
Hydrogen are
the backbone of
organic
molecules
Metalloids (Stair-step In Green)
Have both metal
and non-metal
properties,
depending on
conditions
Such as semiconductors in
electronics
(silicon)
Alkali Metals
Group 1 (not including hydrogen)
S-block (all have s1 ; 1s1, 2s1, 3s1….. Valence electron
configuration)
Lower densities than other metals
One loosely bound valence electron and will readily
form +1 ions, called cations, to bond with nonmetals that “need” an octect
Largest atomic radii in their periods
Low ionization energies
Low electronegativity
Highly reactive with air and water, Will form
solutions with high pH in H2O (bases),
Cs will catch on fire when it is exposed to air!
Alkaline Earth Metals
Group 2
S-block (all have valence electron
configuration of s2)
Two electrons in the outer shell
Readily form +2 cations. Will give up 2
electrons to nonmetals that need to fill their
valence shell (octect rule!)
low electron affinities
Low electronegativity
Transition Metals
D-block – Contains ALL s and
p orbitals; stable elements
half filled or half-filled d
orbitals
Form metallic bonds with
other metals (a sea of
electrons)
All are solid at room temp.
except for Hg (liquid)
Will form cations that vary in
number of valence electron’s
(+1, +2, +3 )
Halogens
Very electronegative (Fluorine the most)
Readily gains an electron to form a -1 Anion
Diatomic in Nature F2 Cl2 Br2 I2
At2
Called Halogens as they will bond with
metals to produce salts, such NaCl or CaCl2
Synthetic (man-made)
Noble Gasses
Valence is completely filled with 2s2 for He
and the rest are 3s23p6, 4s24p6, etc.
satisfying the octet rule
All of the other atoms are jealous 
Inert, meaning not naturally reactive
Periodic Trends –
Atomic Mass Tends to Increase as
Atomic Number Increases
Periodic Trends – Atomic Radii
Decreases
Increases
Increases
Decreases
Periodic Trends – Ionization Energy
Energy required to “pluck” high energy electrons
from the valence shell of an atom in its gaseous stage
Increases across the table BECAUSE…. the atomic
radius decreases across, and atoms are more tightly
compact. It’s harder to remove an electron that is so
close to the nucleus. Great attraction there!!
Opposite in larger atoms, so ionization energy decreases
as you go down (vertically) the table
Halogens already have 7 valence electrons…..rather
gain than lose one, so it takes LOTS of energy to get
them to “let go” of their electrons!
Periodic Trends – Electron Affinity
Typically applies to groups A6 and A7 since they need
electrons to gain an octet
Energy released when an electron is gained by a
neutral atom to produce an anion
Elements are in a gaseous phase
Periodic Trends - Electronegativity
Electronegativity increases across the table (Fluorine is the
MOST electronegative)
measure of the tendency of an atom to attract a bonding pair of
electrons.
Those atoms in groups 6A and 7A are the most electronegative
because they only need 2 or 1 electrons to complete their octect.
Fluorine is assigned a value of 4.0, and values range down to
cesium and francium which are the least electronegative at 0.7
(From the Pauling Scale)
Ionic Radii  Radius of the atom in it’s
ionic state; after it either gained or lost or
gained an electron or electrons
Some Before and After Examples
Atomic and Ionic Radii Comparison (excluding transition
metals). Atoms on the left and their ions on the right.
Notice the size difference!!! Why does this occur???
Atomic Radii Versus Ionic Radii of Main Group Elements