Atomic radius of main-group elements generally
A)increases from left to right across a period and increases down a group.
B)increases from left to right across a period and decreases down a group.
C)decreases from left to right across a period and increases down a group.
D)decreases from left to right across a period and decreases down a group.

Question

Quizplus · Accepted Answer

The atomic radius generally decreases from left to right across a period due to the increase in the number of protons in the nucleus and the stronger attraction between the positively charged nucleus and the negatively charged electrons. On the other hand, the atomic radius generally increases down a group due to the addition of more energy levels and the shielding effect of inner electrons.

Atomic Radius of Main-Group Elements Generally