Question

Which species have the same electron arrangements?
I. O2-, F-. Ne
II. Li+, Na+, K+
III. S2-, Ar, K+

A. I and II only
B. I and III only
C. II and III only
D. I, II and III

Answer 1

Answer:

the answer will be B.1 and 3 only

Explanation:1. O2- means it has in total 10 electrons as atomic no of oxygen is 8

again F- has also 10 electrons as flourine has atomic no 9

and neon  also  has 10 electrons

incase of 3rd no S2- has 18 electrons as atomic no of sulfur is 16 as its an ion so it will take 2 more electrons

argon is an inert gas so it has 18 electrons and potassium has 19 electrons eliminating 1 we will 18

# incase of the second option lithium + contains 2 electrons and Na+ contains 10 and K+ contains 18 electrons so all of them are not same

ANS is 1 and 3 only(B.i and iii) only

thank u