Question

When a potassium atom loses one electron to form an `K^+` ion, the electron is lost from what orbital?

Answer 1

It is lost from `4s`

Explanation:

The electron configuration of `K` is: `1s^2,2s^2, 2p^6,3s^2,3p^6,4s^1`

An atom will lose electrons from its last or furthest orbital from the nucleus.

The furthest orbital in `K` is `4s`, so the electron will be lost from `4s`.