71. | An atom has 9 electrons and 10 neutrons, its mass number will be |
A. 9 | |
B. 10 | |
C. 18 | |
D. 19 |
72. | The number of neutrons and protons in the nucleus of ₈₈Ra²²⁶ (radium) are respectively |
A. 138 and 88 | |
B. 88 and 138 | |
C. 226 & 88 | |
D. 88 and 226 |
73. | The element which has 2 protons, 2 neutrons and 2 electrons in its atom, what will be the mass number of that element? |
A. 2 | |
B. 4 | |
C. 6 | |
D. 8 |
74. | The number of electrons in ₁₉K⁴º is – |
A. 18 | |
B. 19 | |
C. 20 | |
D. 10 |
75. | If the third orbit of an atom is the outermost orbit, then the maximum number of electrons it can hold is |
A. 8 | |
B. 16 | |
C. 18 | |
D. 36 |
76. | The atomic number of an atom is Z and its mass number is M, then what will be the number of neutrons in its nucleus? |
A. M+Z | |
B. M-Z | |
C. M x Z | |
D. M/Z |
77. | A chlorine atom of atomic number 17 and mass number 35 has in its nucleus |
A. 18 protons | |
B. 18 neutrons | |
C. 35 protons | |
D. 35 neutrons |
78. | Which of the following electronic configuration is not possible? |
A. 1s² | |
B. 1s², 2s²2p⁶2d¹º,3s² | |
C. 1s², 2s²2p⁵ | |
D. 1s², 2s²2p⁶2d¹º,3s¹ |
79. | What is the electronic configuration of 1s², 2s²2p⁶? |
A. Na and Ne | |
B. Ne and Na⁺ | |
C. Ne and F | |
D. Na+ and F |
80. | The electronic configuration of an atom with atomic number 20 is – |
A. 2,8,10 | |
B. 2,6,8,4 | |
C. 2,8,8,2 | |
D. 2,10,8 |