Question

Which of the following is iso-electronic with neon?
(C) Mg
(D) Na
(A) 02-
(B) F-​

Answer 1

Answer: Both (A) O2-  and  (B) F-  are iso-electronic with Ne

The electronic configuration for Ne is 1s^2 2s^2 2p^6

Electronic configuration for O is 1s^2 2s^2 2p^4

Electronic configuration for F is 1s^2 2s^2 2p^5

Thus Oxygen requires two electrons to complete a stable octet (fully filled p-orbital) and Fluorine requires one electron to complete a stable octet (fully filled p-orbital) in order to attain the electronic configuration of Ne (Noble gas).

Thus O2- (gain of 2 electrons) and F- (gain of 1 electron) are iso-electronic species with Ne.

Answer 2

Answer:

o2-

Explanation:

just calculate the number of electrons present in each element.

we know neon has 10 electrons.

here o2-has Also 10 electrons.

o has 8 electrons and written that 2 electrons are gained so 8+2=10

you can check other options.

all other will not have 10 electrons.

so your answer is option a o2-

:-)