Periodic Trends
Ionization energy, atomic radius, ionic radius, electronegativity
By Oscar Trejo
Period 2

Ionization Energy (Periods)
 As you go across the periodic table the ionization energy increases.
 Boron has 800.6 and across from it nitrogen has an ionization energy of 1402.

Ionization Energy (Groups)
 As you go down the periodic table the ionization energy decreases. Boron 800.6 to Thallium's
589.4.

Atomic Radius (Periods)
 Atomic radius across the periodic table decreases. Gallium is
130 and across the period to Arsenic which has an atomic radius of 125.

Atomic Radius (Groups)
 Atomic radius in the groups of the periodic table increase as they go down. Arsenic 125 increases to 143 in Bismuth.

Ionic Radius (Period)
 As you go across the periodic table the ionic radius in a period increases.
 The element nitrogen has an ionic radius of
25 to fluorine’s 133.

120
100
80
60
40
20
0
Ionic radius
Ionic Radius (Groups)
Arsenic
Bismuth
3-D
Column 3
 The ionic radius in the periodic table tends to increase as you go down the families.
 Arsenic has an ionic radius of 78, which increases to Bismuth’s
103.

Electronegativity (Periods)
 Electronegativiy in the periodic table increase along the periods.
 Gallium’s electronegativity is
1.81 it increases along the period to arsenic’s
2.2
3
2.5
2
1.5
1
0.5
0 gallium arsenic bromine

Electronegativity (Groups)
 In the electronegativity of the periodic table, the groups decrease as you go down them.
 Boron 2.04, gallium
1.81, thallium 1.62 as you can see elements electronegativity does decrease.

Density (Periods)
 Density across the periodic table for the most part does decrease.
 Boron has a density of 2.34, Nitrogen has a density of 1.25, while fluorine is 1.70.
10
5
0
Density
Nitrogen
Arsenic
Bismuth

Density (Groups)
 Going down the element families the density increases as you go down them. Nitrogen 1.25,
Arsenic 5.73, Bismuth 9.75.

The Periodic Trends
 Ionization energy in periods increases, but in groups decrease.
 Atomic radius in periods decrease while in groups the radius in elements increases.
The same can be said for density.
 Ionic radius in periods increases and the ionic radius decreases in groups.
 Electronegativity increase in periods and decrease in groups.