Atoms  MCQs

MCQs of Atoms

Showing 51 to 60 out of 146 Questions
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51.
A beam of 13.0 eV electron is used to bombard gaseous hydrogen. The series obtained in emission spectra is/are _____.
(a) Lyman
(b) Balmer
(c) Brackett
(d) All of the above
Answer:

Option (d)

52.
A photon of energy 16 eV ionizes a hydrogen atom in the lowest energy state. The kinetic energy of electron coming out of the atom will be _____
(a) 13.6 eV
(b) 2.4 eV
(c) 16 eV
(d) 29.6 eV
Answer:

Option (b)

53.
The excitation energy in the third orbit of hydrogen atom will be _____
(a) 1.51 eV
(b) 3.4 eV
(c) 0.66 eV
(d) 0.85 eV
Answer:

Option (c)

54.
An electron revolves around a nucleus of charge +Ze. If the energy required to excite the electron from second to third Bohr orbit is 47.22 eV, then the value of Z will be _____
(a) 1
(b) 3
(c) 4
(d) 5
Answer:

Option (d)

55.
If the ionization potential in the ground state of hydrogen is 13.6 eV, then the excitation potential of the third orbit will be _____
(a) 0.66 volt
(b) 1.8 volt
(c) 10.2 volt
(d) 13.6 volt
Answer:

Option (a)

56.
On increasing the filament current in X-ray tube _____
(a) wavelength of X-rays increases
(b) penetration power of X-rays increases
(c) intensity of X-rays decreases
(d) intensity of X-rays increases
Answer:

Option (d)

57.
The difference between soft and hard X-rays is of _____
(a) velocity
(b) intensity
(c) frequency
(d) polarization
Answer:

Option (c)

58.
Characteristic X-rays are produced when _____
(a) high potential difference is applied across the tube
(b) low potential difference is applied across the tube
(c) high energy electrons are stopped by the nucleus
(d) high energy electrons strike the inner shell electrons of the atom
Answer:

Option (d)

59.
According to Moseley's law, the frequency of a spectral line in X-ray spectrum varies as _____
(a) atomic number of the element
(b) square of atomic number of the element
(c) square root of atomic number of element
(d) fourth power of the atomic number of element
Answer:

Option (a)

60.
Position of potassium and argon were changed according to _____
(a) Moseley's law
(b) Hund's law
(c) Compton effect
(d) Fazan's law
Answer:

Option (a)

Showing 51 to 60 out of 146 Questions
3 4 5 6 7 8