Which element is more metallic between Sn or As and why?

Question

Which element is more metallic between Sn or As and why?

I know metallic characteristics consist of low effective nuclear charge, low ionization energy, low electron affinity, and large size, however I can't decide between As and Sn. I would think it would be Sn but is that correct? If not, can someone please state the right answer and the correct reasoning behind it?

Answer 1

Metallic character is, in short, the tendency to give up its valence electrons. So, the element whose valence electrons are less strongly attracted to the nucleus would be the more metallic. Since Sn has its valence electrons in the 5th shell (quantum level) and As in the 4th, has a lower effective nuclear charge since its nucleus is farther from the outer shell.