Question

Atomic radius
a. increases across a period and increases down a group.
b. decreases across a period but increases down a group.
c. increases across a period but decreases down a group.
d. decreases across a period and decreases down a group.

Answer 1

The correct answer is B. The atomic radius decreases across a period but increases down a group. The periodic table is arranged in order to predict certain properties of the elements across a period or  down a group. Aside from the atomic radius, other trends include electron affinity, ionization energy, electronegativity and metallic character.