16. Velocity of electron in second bohr orbit as compared to velocity in first orbit is :
(a) one fourth
(b) one half
(c) equal
(d) 2 times
17. In gamma ray emission form a nucleus :
(a) Only Proton number change
(b) Only neutron number change
(c) Both the number are changes
(d) There is no change in the proton-number and neutron number
18. Bohr’s atomic model is based upon :
(a) Einstein’s relativistic theory
(b) classical theory
(c) planks quantum theory
(d) both b and c
19. The nuclear of which of following Pairs of nuclei are isotones :
(a) 34Se74 , 31Ca71
(b) 42Mo92 , 40Zr92
(c) 38Sr81 , 38Sr86
(d) 20Cd40 , 16S32
20. The atomic number is equivalent to which of the following ?
(a) The number of neutrons in the atom
(b) The number of protons in the atom
(c) The number of nucleons in the atom
(d) The number of ?–particles in the atom
Related Posts
Atomic Physics » Exercise - 19. The ionization energy of hydrogen atom is 13.6 eV. The ionization energy of helium atom would be : (a) 13.6 eV (b) 27.2 eV (c) 54.4 eV (d) 62.8 eV - Atomic Physics » Exercise - 112. If 13.6eV energy is required to ionize the hydrogen atom the energy required to remove the electron form n=2 state is : (a) Zero (b) 3.4eV (c) 6.8eV (d) 10.2eV
- Atomic Physics » Exercise - 114. Ionization energy of hydrogen atom in ground state is : (a) 13.6 J (b) 13.6 eV (c) 13.6 MeV (d) 13.6 V
- Atomic Physics » Exercise - 120. The atomic number is equivalent to which of the following ? (a) The number of neutrons in the atom (b) The number of protons in the atom (c) The number of nucleons in the atom (d) The number of ?–particles in the atom
- Atomic Physics » Exercise - 17. Electron in atom are held in atom due to : (a) atomic force (b) nuclear force (c) coulombs force (d) none fo these