Carbon (C) · 6 electrons · Reactive nonmetal
1s2 2s2 2p2
Noble gas notation: [He] 2s2 2p2

Orbital diagram

Valence electrons
4
Unpaired electrons
2
Block
p-block
Magnetism (atom)
paramagnetic

Electrons per shell

C
K (n = 1)2
L (n = 2)4

Carbon ion configurations

IonElectronsConfiguration
C4+21s2
C4−10[He] 2s2 2p6

How to write it

Place 6 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. Carbon sits in period 2, group 14, in the p-block, so its last electron enters a p subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [He] 2s2 2p2.

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

Carbon electron configuration FAQ

What is the electron configuration of carbon?

1s² 2s² 2p². Shorthand (noble gas) notation: [He] 2s² 2p².

What is the noble gas configuration of carbon?

[He] 2s² 2p². The bracket stands for the He core electrons.

How many valence electrons does carbon have?

4 (outer shell (n = 2)).

How many unpaired electrons does carbon have?

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

What is the electron configuration of C4+?

1s² (2 electrons).

What is the electron configuration of C4−?

[He] 2s² 2p⁶ (10 electrons).