Question

Element having electronic configuration $1s^2,2s^2,2p^6,3s^2,3p^6,3d^{10},4s^2,4p^6,4d^{10},5s^2,5p^3$ belongs to the group in the periodic table:

• A. $3$rd A group
• B. $2$nd A group
• C. $5$th A group
• D. $7$th A group

Answer 1

The correct option is C $5$th A group

A number of electrons present in valence shell of penultimate Shell represents the group of elements.

For $s$ block elements: no.of group=number of valence shell electron.

$p$ block elements: no. of group= 2 + 10 + number of valence electrons.

$d$ block elements: no. of group= number(n-1)d electrons + number of electrons in nth shell.

Here, the differential electron is in p orbital hence, it belongs to p block

No. of group= 2+ 10 + 3=15 i.e 15th group or $VA$ group