| 61. | Which of the following is the electronic configuration for a metal element? |
A. 2,8,1 | |
B. 2,8 | |
C. 2,8,8 | |
D. 2,8,8,2 |
| 62. | The electronic structure of ₁₃AI²⁷ is – |
A. 2,8,2,1 | |
B. 2,8,3 | |
C. 2,8,1,2 | |
D. 3,8,2 |
| 63. | Which of the following is the electronic structure of sodium ion? |
A. 2,8,1 | |
B. 2,8 | |
C. 2,8,8 | |
D. 2,8,7 |
| 64. | Rutherford discovered the nucleus by studying the scattering of |
A. α rays | |
B. β rays | |
C. γ rays | |
D. X rays |
| 65. | When an electron moves from a higher orbit to a lower orbit, then |
A. energy is released | |
B. energy is absorbed | |
C. the size of the atom decreases | |
D. none of these |
| 66. | Consider the following electronic configurations – 1. ↑ ↑↓ ↑ ↑ 2. ↑↓ ↑ ↑ ↑ 3. ↓ ↑↑↑ Configurations that do not obey Hund’s principle – |
A. 1,2 and 3 | |
B. 2 and 3 | |
C. 1 and 2 | |
D. 1 and 3 |
| 67. | The number of core electrons in sodium atom is |
A. 1 | |
B. 2 | |
C. 8 | |
D. 10 |
| 68. | The electronic configuration of an atom is 2, 8, 2, then the number of valence electrons in it is |
A. 10 | |
B. 12 | |
C. 8 | |
D. 2 |
| 69. | An atom has 19 protons and 20 neutrons, then its mass number will be |
A. 39 | |
B. 19 | |
C. 20 | |
D. 12 |
| 70. | The atomic number of element A is 1 3, then it will have valence electrons |
A. 0 | |
B. 1 | |
C. 2 | |
D. 3 |