What is Ne 3s2 and Ne 3s2 and Ar 3d6 4s2 noble gas notation for?

Answer 1

Ne 3s2 would be Magnesium, and Ar 3d6 4s2 is Iron.

For the first one you look at neon and count 2 "s" electrons after, which puts you at Mg.

For the latter, you look at Argon, count 2 "4s" electrons then 6 "3d" electrons. and you'll end up on Fe.

Answer 2

Ne 3s^2 represents the electron configuration for neon where the 3s subshell is filled with 2 electrons. Similarly, Ar 3d^6 4s^2 represents the electron configuration for argon where the 3d and 4s subshells are filled with 6 and 2 electrons respectively. These configurations are written in noble gas notation to show the number of electrons in the outermost energy levels.