Question

identify which of the following could be the electron configuration for an element in the p - block.
i. ( 1 s ^ { 2 } 2 s ^ { 2 } 2 p ^ { 6 } 3 s ^ { 1 } )
ii. xe
iii. ( 1 s ^ { 2 } 2 s ^ { 2 } 2 p ^ { 6 } 3 s ^ { 2 } 3 p ^ { 6 } 4 s ^ { 2 } 3 d ^ { 10 } 4 p ^ { 1 } )
iii only
ii only
i and iii
i and ii
i, ii and iii
i only
ii and iii

Explanation:

Step1: Analyze electron configuration I

The electron configuration \(1s^{2}2s^{2}2p^{6}3s^{1}\) has the last - filled orbital as \(3s\). Elements with the last - filled orbital as \(s\) belong to the \(s\) - block.

Step2: Analyze electron configuration II

The electron configuration \([Xe]\) represents a noble gas. Noble gases have completely filled orbitals (\(s^{2}p^{6}\) in the valence shell). But noble gases are usually considered in their own group (Group 18). However, if we consider the general rule for block classification based on the last - filled orbital for non - noble gas \(p\) - block elements (where the last - filled orbital is \(p\)), \([Xe]\) does not follow the typical \(p\) - block electron - filling pattern (where we have \(ns^{2}np^{x}\) for \(p\) - block elements, \(n\geq2\)).

Step3: Analyze electron configuration III

The electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{1}\) has the last - filled orbital as \(4p\). For elements, if the last - filled orbital is \(p\) (\(ns^{2}np^{x}\), \(n\geq2\)), the element belongs to the \(p\) - block.

Answer:

III only