Compared to the average size of a hydrogen atom, the average size of a helium atom is
A)larger.
B)smaller.
C)about the same.

Question

Quizplus · Accepted Answer

The average size of a helium atom is smaller than that of a hydrogen atom because helium has a higher number of protons and neutrons in its nucleus, leading to a stronger nuclear charge. This attracts electrons more strongly, causing the electron cloud to be more tightly packed and the atom to be smaller overall.

Compared to the Average Size of a Hydrogen Atom, the Average