Which of the following particles are constituents of the nucleus
(a) Protons and electrons           (b) Protons and neutrons
(c) Neutrons and electrons         (d) Neutrons and positrons

Concept Questions :-

Various atomic model

Difficulty Level:

The ratio of the speed of the electrons in the ground state of hydrogen to the speed of light in vacuum is

1. 1/2                2. 2/137
3. 1/137            4. 1/237

Concept Questions :-

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

Difficulty Level:

A hydrogen atom in its ground state absorbs 10.2 eV of energy. The orbital angular momentum is increased by

1. $1.05×{10}^{-34}$ J-sec                 2. $3.16×{10}^{-34}$ J-sec
3. $2.11×{10}^{-34}$ J-sec                 4. $4.22×{10}^{-34}$J-sec
(Given Planck constant h = $6.6×{10}^{-34}$ J-sec)

Concept Questions :-

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

Difficulty Level:

Hydrogen (H), deuterium (D), singly ionized helium and doubly ionized lithium all have one electron around the nucleus. Consider n =2 to n = 1 transition. The wavelengths of emitted radiations are ${\mathrm{\lambda }}_{1},{\mathrm{\lambda }}_{2},{\mathrm{\lambda }}_{3}$ and ${\mathrm{\lambda }}_{4}$ respectively. Then approximately
(a) ${\mathrm{\lambda }}_{1}={\mathrm{\lambda }}_{2}=4{\mathrm{\lambda }}_{3}=9{\mathrm{\lambda }}_{4}$                             (b) $4{\mathrm{\lambda }}_{1}=2{\mathrm{\lambda }}_{2}=2{\mathrm{\lambda }}_{3}={\mathrm{\lambda }}_{4}$
(c) ${\mathrm{\lambda }}_{1}=2{\mathrm{\lambda }}_{2}=2\sqrt{2}{\mathrm{\lambda }}_{3}=3\sqrt{2}{\mathrm{\lambda }}_{4}$                 (d) ${\mathrm{\lambda }}_{1}={\mathrm{\lambda }}_{2}=2{\mathrm{\lambda }}_{3}=3\sqrt{2}{\mathrm{\lambda }}_{4}$

Concept Questions :-

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

Difficulty Level:

Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Bohr atom model and consider all possible transitions of this hypothetical particle to the first excited level. The longest wavelength photon that will be emitted has wavelength $\mathrm{\lambda }$ (given in terms of the Rydberg constant R for the hydrogen atom) equal to

(a) 9/(5R)                 (b) 36/(5R)
(c) 18/(5R)                (d) 4/R

Concept Questions :-

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

Difficulty Level:

The transition from the state n = 4 to n = 3 in a hydrogen-like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition
(a) 2$\to$1                  (b) 3$\to$2
(c) 4$\to$2                  (d) 5$\to$4

Concept Questions :-

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

Difficulty Level:

In the Bohr model of the hydrogen atom, let R, v and E represent the radius of the orbit, the speed of electron and the total energy of the electron respectively. Which of the following quantity is proportional to the quantum number n ?

(a) R/E               (b) E/v
(c) RE                (d) vR

Concept Questions :-

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

Difficulty Level:

The electric potential between a proton and an electron is given by $\mathrm{V}={\mathrm{V}}_{0}\mathrm{ln}\frac{\mathrm{r}}{{\mathrm{r}}_{0}}$ where ${\mathrm{r}}_{0}$ is a constant. Assuming Bohr’s model to be applicable, write variation of ${\mathrm{r}}_{\mathrm{n}}$ with n, n being the principal quantum number

(a) ${\mathrm{r}}_{\mathrm{n}}\propto \mathrm{n}$            (b)  ${\mathrm{r}}_{\mathrm{n}}\propto 1/\mathrm{n}$
(c) ${\mathrm{r}}_{\mathrm{n}}\propto {\mathrm{n}}^{2}$           (d) ${\mathrm{r}}_{\mathrm{n}}\propto 1/{\mathrm{n}}^{2}$

Concept Questions :-

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

Difficulty Level:

If the atom ${}_{100}{}^{257}\mathrm{Fm}$ follows the Bohr model and the radius of ${}_{100}{}^{257}\mathrm{Fm}$ is n times the Bohr radius, then find n

(a) 100                  (b) 200
(c) 4                      (d) $\frac{1}{4}$

Concept Questions :-

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

Difficulty Level:

Bohr's atom model assumes
(a) The nucleus is of infinite mass and is at rest
(b) Electrons in a quantized orbit will not radiate energy
(c) Mass of electron remains constant
(d) All the above conditions

Concept Questions :-

Bohr's model of atom