The number of electrons in the valence shell of calcium is

(A) 6

(B) 8

(C) 2

(D) 4

Concept Questions :-

Number of E/P/N
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Difficulty Level:

The brackett series of spectral lines arise when an electron in an excited hydrogen atom jumps from an energy level

(A) n=5 to n=1

(B) n=5 to n=3

(C) n=5 to n=4

(D) n=5 to n=2

Concept Questions :-

Hydrogen Spectra
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Difficulty Level:

What is the ratio of the time period of revolution of electron He+ ion sample in the orbit where the path length is three time the de-broglies wavelength to the time period of revolution in the ground state –

(A) 27:1

(B) 1:27

(C) 9:8

(D) 8:9

Concept Questions :-

de Broglie Equation
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Difficulty Level:

The ratio of the wavelengths of last lines of Balmer and Lyman series is-

(A) 4:1

(B) 27:5

(C) 3:1

(D) 9:4

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Difficulty Level:

According to Moseley, a straight line graph is obtained on plotting-

(A) The frequencies of characteristic X-rays of elements against their atomic numbers.

(B) The square of the frequencies of characteristic X-rays of elements against their atomic numbers

(C) The square root of the frequencies of characteristic X-rays of elements against their atomic numbers

(D) The reciprocal of the frequencies of characteristic X-rays of elements against their atomic numbers.

Concept Questions :-

introduction
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Difficulty Level:

The energy of the emitted photon when an electron in Be3+ ion returns from n=2 level to ground state is -

(A) 2.616 x 10-17J

(B) 26.16 x 10-17J

(C) 261.6 x 10-17J

(D) 2616 x 10-17J

Concept Questions :-

Bohr
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Difficulty Level:

The accelerating potential to be imparted to a beam of electrons to give an effective wavelength of 2.42 nm is

(A) 2.56V

(B) 3.42V

(C) 0.256V

(D) 0.342V

Concept Questions :-

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Difficulty Level:

The splitting of spectral lines in a magnetic field, arising out of orbital motion of electrons only and the further splitting due to spin motion are respectively called

(A) Zeeman and Stark effects

(B) Zeeman and anomalous Zeeman effects

(C) Stark and Zeeman effects

(D) Zeeman and Kerr effects

Concept Questions :-

Type of Spectra
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Difficulty Level:

A photon of wavelength 300 nm causes the emission of two photons. If the wavelength of one of them is 700 nm. What is the wavelength of the other photon?

(A) 525 mm

(B) 600 nm

(C) 450 nm

(D) 300 nm

Concept Questions :-

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Which transition of electron in the hydrogen atom emits maximum energy:

(A) 2 $\to$ 1

(B) 1 $\to$ 4

(C) 4 $\to$ 3

(D) 3 $\to$ 2

Concept Questions :-

Hydrogen Spectra