Atomic Structure Question 100
Question: An element have atomic weight 40 and it-s electronic configuration is $ 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}. $ Then its atomic number and number of neutrons will be [RPMT 2002]
Options:
A) 18 and 22
B) 22 and 18
C) 26 and 20
D) 40 and 18
Show Answer
Answer:
Correct Answer: A
Solution:
$ Ar_{18}^{40} $ = atomic number 18 and no. of Neutron in case of $ Ar_{22} $
Neutron = Atomic mass - Atomic number $ =40-18=22 $