Question

Which theory is proposed by Kossel and Lewis?
(A) Atomic theory
(B) Electronic theory
(C) Theory of reactivity
(D) None of these

Answer 1

Kossel and Lewis successfully explained an approach based on the concept of the electronic configuration of noble gases about how the atoms combined to form molecules in 1916. They explained briefly about the stability of noble gases.

Complete step by step solution:
According to the Kossel and Lewis approach, Atoms of noble gases have little or no tendency to combine atoms of other elements. That means every atom occupies inert electronic configuration $n{{s}^{2}}n{{p}^{6}}$ of the nearest inert gas which is considered as a stable octet.
The electronic configuration of noble gases is given below:

Name of the element	Atomic symbol	Atomic number	Electronic configuration
Helium	He	2	$1{{s}^{2}}$
Neon	Ne	10	$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}$
Argon	Ar	18	$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}$
Krypton	Kr	36	$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}4{{p}^{6}}$
Xenon	Xe	54	$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}4{{p}^{6}}4{{d}^{10}}5{{s}^{2}}5{{p}^{6}}$
Radon	Rn	86	$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}4{{p}^{6}}4{{d}^{10}}5{{s}^{2}}5{{p}^{6}}5{{d}^{10}}6{{s}^{2}}6{{p}^{6}}$

Due to stable configuration, the noble gases either lose or gain electrons, so valence is zero. There are so inert monatomic gaseous atoms. This approach is known as the electronic theory of valence by Kossel and Lewis.

Hence, the correct answer is B.

Note: This electronic theory of valence was developed by Kossel and Lewis and applied by Langmuir. The stable inert electronic configuration is attained by either transfer of electrons, sharing of electrons, or donation of lone pairs of electrons. This theory fails to explain the tetravalency of carbon and does not discuss the electrons’ energies. The shapes and the bond angles of the molecules were not explained by this theory.