Which of these elements has four valence electrons?

Question

A. hafnium (Hf)

B. radon (Rn)

C. silicon (Si)

D. sulfur (S)

I thought that Hafnium and silicon both had four valence electrons in their outer shell, but I can't pick them both.

Answer 1

Yep, I agree with you. Quite a conundrum.

If I had to pick one, I'd go with Si, just because it's more common.