Question

Predict whether hardness of Group 1A elements will increase up the group.

A) Increase
B) Decrease
C) Remain constant
D) Fluctuate

Answer 1

The hardness of Group 1A elements will decrease as you move up the group due to smaller atomic radii and more tightly held valence electrons in the elements at the top.

Step-by-step explanation:

The hardness of Group 1A elements will decrease up the group. As you move up Group 1A on the periodic table, the elements have smaller atomic radii and the valence electron is closer to the nucleus and more tightly held. This makes the elements at the top of Group 1A, like lithium, harder than those at the bottom, like cesium, where the valence electrons are further from the nucleus and more easily removed, resulting in softer elements.