Lithium (Li) · 3 electrons · Alkali metal
1s2 2s1
Noble gas notation: [He] 2s1

Orbital diagram

Valence electrons
1
Unpaired electrons
1
Block
s-block
Magnetism (atom)
paramagnetic

Electrons per shell

Li
K (n = 1)2
L (n = 2)1

Lithium ion configurations

IonElectronsConfiguration
Li+21s2

How to write it

Place 3 electrons into subshells in the Aufbau order (1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p), filling s with 2, p with 6, d with 10 and f with 14. Lithium sits in period 2, group 1, in the s-block, so its last electron enters an s subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [He] 2s1.

Try lithium and its ions in the calculator, or see the full lithium data sheet.

Lithium electron configuration FAQ

What is the electron configuration of lithium?

1s² 2s¹. Shorthand (noble gas) notation: [He] 2s¹.

What is the noble gas configuration of lithium?

[He] 2s¹. The bracket stands for the He core electrons.

How many valence electrons does lithium have?

1 (outer shell (n = 2)).

How many unpaired electrons does lithium have?

1 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.

What is the electron configuration of Li+?

1s² (2 electrons).