Question

An element with an electron configuration of `1s^2 2s^2 2p^6 3s^1` will have properties most similar to which element?

Answer 1

sodium (Na)

Explanation:

Given: electron configuration `1s^2 2s^2 2p^6 3s^1`

The periodic table can generally be used to find the electron configuration of an element. There are a few special cases:

1st column, hydrogen + alkali metals: `1s^1`

2nd column, alkaline earth metals: `1s^2`

3rd-12th columns, transition metals: `d^1 -> d^6`

13th-18th columns, Boron - neon: `p^1 -> p^6`

Inner transition metals: `f^1 -> f^14`

Look at the last set of electrons (valence) in your example: `3s^1`

This means the element falls within the column 1: alkali metals. The `3` represents the number of energy levels (periodic table row).

This means `1s^2 2s^2 2p^6 3s^1` = the electron configuration for sodium (Na).