When an $\alpha$-particle of mass m moving with velocity v bombards on a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on m as:

(a)$\frac{1}{\sqrt{m}}$
(b)$\frac{1}{\sqrt{{m}^{2}}}$
(c)m
(d)$\frac{1}{m}$

Concept Questions :-

Various atomic model
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Consider 3rd orbit of He+ (Helium), using the non-relativistic approach, the speed of the electron in this orbit will be given K=9x109 constant Z=2 and h (Planck's constant=6.6x10-34 J-s)

(a)2.92x108 m/s

(b)1.46x108 m/s

(c)0.73x108 m/s

(d)3.0x108 m/s

Concept Questions :-

Bohr's model of atom
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Difficulty Level:

In the spectrum of hydrogen. the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is:-

(a) 4/9
(b) 9/4
(c) 27/5
(d) 5/27

Concept Questions :-

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

Difficulty Level:

Hydrogen atom in ground state is excited by a monochromatic radiation of λ=975Å. The number of spectral lines in the resulting spectrum emitted will be:

(a)3

(b)2

(c)6

(d)10

Concept Questions :-

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

Difficulty Level:

Ratio of longest wavelengths corresponding to Lyman and Balmer series in twinge!) spectrum ts

(a)5/27

(b)3/23

(c)7/29

(d)9/31

Concept Questions :-

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

Difficulty Level:

Electron in hydrogen atom first jumps from third exicted state to second exicted state and then from second exicted to the first excited state. The ratio of the wavelengths ${\lambda }_{1}:{\lambda }_{2}$ emitted in the two cases is

(a) 7/5

(b) 27/20

(c) 27/5

(d) 20/7

Concept Questions :-

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

Difficulty Level:

An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be

(a)                                (b)

(c)$\frac{25m}{24hR}$                                 (d)$\frac{24m}{25hR}$

(m is the mass of the electron, R Rydberg constant and h Planck's constant)

Concept Questions :-

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

Difficulty Level:

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V.The threshold frequency of the material is:

(a)$4×{10}^{15}Hz$                               (b)$5×{10}^{15}Hz$

(c)$1.6×{10}^{15}Hz$                            (d)$2.5×{10}^{15}Hz$

Concept Questions :-

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

Difficulty Level:

The transition from the state n=3 to n=1

a hydrogen like atom results in ultraviolet

in the transition from

(a) $2\to 1$

(b) $3\to 2$

(c) $4\to 2$

(d) $4\to 3$

Concept Questions :-

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

Difficulty Level:

The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen-like ion. The atomic number Z of hydrogen-like ion is

(a) 4                                                  (b) 1

(c) 2                                                  (d) 3

Concept Questions :-

Spectral series