Question

iv.
Which electron in an atom (Z=17) is the most shielded from
nuclear charge?
A.
an electron in the 2s
B.
an electron in the 3p
C.
an electron in the 3d
D.
an electron in the 1s​

Answer 1

Answer:D

Explanation:

An electron 1s  is an atom z=17.

Answer 2

Atom with Z = 17.

First, let's write the electronic configuration.

$\boxed{ \rm\: X_{17} \rightarrow 1 {s}^{2} \: 2{s}^{2} \: 2 {p}^{6} \: {3s}^{2} {3p}^{5} }$

Now, the valence electrons will be most shielded in the that atom, especially in this case because:

• First of all, it is the valence electron, hence experiences the least nuclear charge.

• Secondly, it experiences SHIELDING EFFECT from 2s, 2p, 3s (inner) electrons.

So, an electron from '3p' orbital will experience max shielding.