Question

What are the general period and group trends among main-group elements with respect of the following properties?

a. atomic radii
b. first ionization energy
c. electron affinity
d. ionic radii
e. electronegativity

Answer 1

Outlined below, but beware of atomic radii trend.

Explanation:

a. atomic radii

Increases down a group (top to bottom). Decreases across a period (left to right).

b. first ionization energy

Increases across a period (left to right). Decreases down a group.

c. electron affinity

Increases across a period. Decreases down a group.

d. ionic radii

Increases down a group. Decreases across a period until non metals, then increases.

e. electronegativity

Increases across a period. Decreases down a group.