Question

i) Which of the following electronic configuration is not possible?
(a) X: 2, 8,4
(b) Y: 2, 8, 8,2
(c) Z: 2,8,9
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Answer 1

option c can't be possible

Answer 2

Answer:

X=2,8=10: It is the electronic configuration of neon.

Y=2,8,7=17: It is the configuration of the halogen family of chlorine atom which is non-metal

Z=2,8,2=12: It is the configuration of alkaline earth metals of magnesium atom which is metal.

Therefore, X is a noble gas, Y is a non-metal, and Z is a metal.

Option c is correct.