JEE Main & Advanced
Chemistry
Structure of Atom / परमाणु संरचना
Question Bank
Critical Thinking
question_answer
The electronic configuration of a dipositive metal \[{{M}^{2+}}\] is 2, 8, 14 and its atomic weight is 56 a.m.u. The number of neutrons in its nuclei would be [MNR 1984, 89; Kerala PMT 1999]
A) 30
B) 32
C) 34
D) 42
Correct Answer:
A
Solution :
Metal is \[_{56}{{M}^{2+}}\,(2,\,8,\,14)\] than \[n=A-Z\] \[=56-26=30\].