The Atomic Radius of Germanium (Z 32) Is

Multiple Choice

The atomic radius of germanium (Z 32) is smaller than the atomic radius of potassium (Z 19) because of ________

A) a change in the n quantum number.
B) an increase in the effective nuclear charge.
C) the fact that p and d orbitals have the same orbital penetration.
D) a decrease in the effective nuclear charge.
E) germanium having 32 rather than 19 electrons.