Answer to Question #155966 in General Chemistry for martin

Question

In terms of atomic structure and coulombic interactions explain why a silicon atom has a larger atomic radius than a phosphorus

Answer 1

Atomic size increases down the group as the new shell is added successively while this atomic size decreases across the period

According to Coulomb's Law, as the atomic number increases within a series of atoms, the nuclear attraction for electrons will also increase, thus pulling the electron(s) closer to the nucleus. ... Such a relationship between atomic number and atomic radius is a direct correlation.

Silicon Configuration = 1s²2s²2p²3s²3p²

Phosphorus configuration = 1s²2s²2p²3s²3p³

Atomic radius of Silicon = 111pm

Atomic radius of phosphorus = 98pm

So , silicon atom has a larger atomic radius than a phosphorus