Question

The total number of metal having valence $n{{s}^{1-2}}$ configuration except for d and f block element-
(A)- 14
(B)- 13
(C)- 12
(D)- 10

Answer 1

Around 95 of the 118 elements in the periodic table are metals which clearly shows the abundance of metals in nature. However, this number of metals is inexact as there are some borderline elements between metals and nonmetals and metalloids fluctuate slightly due to a lack of universally accepted definitions of the categories involved.

Complete Step by step answer:
-The outer electron associated with an atom which can participate in the formation of a chemical bond if the outer shell is not closed is known as a valence electron.
-Valence electrons are the electrons present in s and p orbitals in the outermost shell of the atom.
-As we move from left to right side in a period on the periodic table, the number of valence electrons increases. However, as we move from up to down in a group, the periodic trend for the number of electrons is constant.
-Valency in the periodic table across a period first and then decreases, however, there is no change in going down a group.
-Excluding metals of d and f orbitals, there are 23 metals in s and p-orbitals.
-Out of those 23 metals of s and p-orbitals there are 14 elements which have valence configuration as $n{{s}^{1-2}}$, which are given below-
(i) Hydrogen
(ii) Lithium
(iii) Sodium
(iv) Potassium
(v) Rubidium
(vi) Cesium
(vii) Francium
(viii) Beryllium
(ix) Magnesium
(x) Calcium
(xi) Strontium
(xii) Barium
(xiii) Radium
(xiv) Helium

Therefore, the correct answer is option A.

Note: The number of valence electrons present in the atom helps us to determine specific elements’ chemical properties, the formation of bonds with other elements. The idea of calculation of valence electrons is important to know how readily the atoms can form bonds and how many atoms can take part.