What is 1s2 2s2 2p6?

Answer 1

Those numbers denote electron orbitals, if my chemistry isn't too rusty that is Na (Sodium).

Answer 2

This electron configuration represents the electron arrangement of a nitrogen atom. It shows that nitrogen has two electrons in its 1s orbital, two electrons in its 2s orbital, and six electrons in its 2p orbital.

Answer 3

It is a mistake. This cannot exist because the 3s cannot have 3 electrons. The s sub-level in any principle energy level can contain no more than 2 electrons.

Answer 4

It is sodium electronic configuration.

Answer 5

Neon