Question

what is the valency of an atom if its successive ionization energies respectively are 800, 900, 925, 25356, 32456 KJ/mole ?
3
4
5
6​

Answer 1

GiveN :

• Successive ionization energies are 800, 900, 925, 25356, 32456 kJ/mole

To FinD :

• Valency of atom

SolutioN :

We're given that the successive ionization energies of an atom are given as 800 , 900 , 925, 25356 , 32456 kJ/mole.

Valency of atom is 3 or we can also say that atom have 3 valence electrons. Because there is a lot of difference in fourth and fifth ionization energies, then in first three ionization energies. So, after losing three electrons atom gain noble gas configuration. So, for removing further electron we've to give more energies.

Answer 2

we have to find the valency of an atom if its successive ionization energies respectively are 800, 900 , 925 , 25356 , 32456 kJ/mole.

solution : before going to check out ionisation energies of given element. let's understand what is the meaning of ionisation energy.

“ it is the amount of energy required to remove an electron from an isolated gaseous atom. ”

condition : if I.E1 , I.E2 , I.E3 are successive ionization energies of an atom.

if I.E1 < (I.E2 - I.E1) ⇒ valency of atom is 1.

if I.E2 < (I.E3 - I.E2) ⇒valency of atom is 2.

if I.E3 < (I.E4 - I.E3) ⇒valency of atom is 3.

here same case is appear.

I.E1 = 800 , I.E2 = 900 , I.E3 = 925 , I.E4 = 25356 and I.E5 = 32456

(I.E2 - I.E1) = (900 - 800) < 800( I.E1 )

so, Valency of the atom can't be 1.

(I.E3 - I.E2) = 925 - 900 = 25 < 900 (I.E2)

also valency of the atom can't be 2.

(I.E4 - I.E3) = (25356 - 925) > 925 (I.E3)

here it is clear that I.E4 - I.E3 < I.E3

Therefore the valency of the atom is 3. so option (1) 3, is correct