Question

Match the entries of Column A with those of Column B.

Column A	Column B
(i) $\mathrm{E}=\frac{\mathrm{hc}}{\mathrm{\lambda }}$	(A) Rutherford
(ii) $\mathrm{mvr}=\frac{\mathrm{nh}}{2\mathrm{\pi }}$	(B) J.J. Thomson
(iii) $\alpha$-ray scattering experiment	(C) Max Plank
(iv) Thinly spread positively charged mass	(D) Niels Bohr

• A. (i) $\to$(C); (ii) $\to$ (D) ;(iii) $\to$ (A) ;(iv) $\to$(B)
• B. (i) $\to$(C) ;(ii) $\to$ (A) ;(iii) $\to$ (D); (iv) $\to$(B)
• C. (i) $\to$(B); (ii) $\to$ (D) ;(iii) $\to$ (A); (iv) $\to$(C)
• D. (i) $\to$(B); (ii) $\to$ (A); (iii) $\to$ (D); (iv) $\to$(C)

Answer 1

The correct option is A

(i) $\to$(C); (ii) $\to$ (D) ;(iii) $\to$ (A) ;(iv) $\to$(B)

The explanation for the correct option: (a)

1. Max Plank gave Plank's quantum theory which states that different atoms emit or absorb energy in discrete quantities only. Also, the energy emitted or absorbed is proportional to the wavelength of radiation as

$\mathrm{E}=\frac{\mathrm{hc}}{\mathrm{\lambda }}$

Hence, the correct match is (i)$\to$(C).

2. $\mathrm{mvr}=\frac{\mathrm{nh}}{2\mathrm{\pi }}$ represents the relation between the angular momentum of an electron ($\mathrm{mvr}$) and the orbit of the electron (n) in which it is revolving. This relation is given by Niels Bohr and his atomic model says that the angular momentum of an electron revolving around the nucleus is quantized. Hence, the correct match is (ii)$\to$(D)

3. $\alpha$-ray scattering experiment is performed by Rutherford to determine the atomic structure and Rutherford postulated that an atom has a dense and small positively charged nucleus around which electrons revolve in fixed orbits. Hence, the correct match is (iii)$\to$(A).

4. J.J Thomson proposes that an atom has positive and negative charges thinly spread across the atom. Hence, the correct match is (iV)$\to$(B).

5. Hence, Column A is matched with Column B as- (i) $\to$(C); (ii) $\to$ (D) ;(iii) $\to$ (A) ;(iv) $\to$(B)

The correct option is (a).