Who discovered spin quantum number
(a) Unlenbeck and Goudsmit
(b) Nell’s Bohr
(c) Zeeman
(d) Sommerfield

Concept Questions :-

Various atomic model

Difficulty Level:

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

(a) n             (b) $\frac{{\mathrm{n}}^{3}}{{\mathrm{Z}}^{2}}$
(c) $\frac{{\mathrm{n}}^{2}}{\mathrm{Z}}$          (d) $\frac{\mathrm{Z}}{\mathrm{n}}$

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In Bohr’s model, if the atomic radius of the first orbit is ${\mathrm{r}}_{0}$, then the radius of the fourth orbit is
(a) ${\mathrm{r}}_{0}$              (b) 4${\mathrm{r}}_{0}$
(c) ${\mathrm{r}}_{0}$/16          (d) 16${\mathrm{r}}_{0}$

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

If R is the Rydberg’s constant for hydrogen the wave number of the first line in the Lyman series will be

(a) $\frac{\mathrm{R}}{4}$                   (b) $\frac{3\mathrm{R}}{4}$
(c) $\frac{\mathrm{R}}{2}$                   (d) 2R

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In hydrogen atom, if the difference in the energy of the electron in n =2 and n = 3 orbits is E, the ionization energy of hydrogen atom is
(a) 13.2 E                (b) 7.2 E
(c) 5.6 E                  (d) 3.2 E

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelengths limit of Paschen series is
(a) 1215 Å     (b) 6560 Å
(c) 8225 Å     (d) 12850 Å

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ratio of the largest to shortest wavelengths in Lyman series of hydrogen spectra is
(a) $\frac{25}{9}$         (b) $\frac{17}{6}$
(c) $\frac{9}{5}$           (d) $\frac{4}{3}$

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in n =2 and n = 1 orbits is

(a) 2 : 1              (b) 4 : 1
(c) 8 : 1              (d) 16 : 1

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra is
(a) $\frac{25}{9}$            (b) $\frac{17}{6}$
(c) $\frac{9}{5}$              (d) $\frac{4}{3}$

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true
(a) Its kinetic energy increases and its potential and total energies decrease
(b) Its kinetic energy decreases, potential energy increases and its total energy remains the same
(c) Its kinetic and total energies decrease and its potential energy increases
(d) Its kinetic, potential and total energies decreases

Concept Questions :-

Spectral series