Electron Configuration of Helium (He)
What is the electron configuration of Helium?
The electron configuration of Helium (He, Z=2) is 1s². In noble gas shorthand: 1s². It has 0 unpaired electron(s) and is a s-block element.
| Symbol | He |
| Atomic Number | 2 |
| Full Electron Configuration | 1s² |
| Noble Gas Shorthand | 1s² |
| Block | s |
| Period | 1 |
| Group | 18 |
| Unpaired Electrons | 0 |
| Exception? | No |
Orbital Filling Order
Following the aufbau principle, the 2 electrons in Helium fill orbitals in order of increasing energy: 1s (2 electrons).
Each orbital is filled according to the Pauli exclusion principle (at most 2 electrons per orbital) and Hund's rule (electrons occupy degenerate orbitals singly before pairing).
Noble Gas Shorthand
Helium is a light element (Z=2) with no noble gas core to abbreviate. Its full configuration 1s² is already concise.
Valence Electrons
The valence shell of Helium contains 2 electrons in the 1s subshell. These outermost electrons determine Helium's chemical reactivity, bonding behavior, and position in the periodic table as a s-block element in period 1.
Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.
Explore Helium in the Electron Configuration ExplorerRelated Topics
Electron Configuration of Hydrogen
Orbital filling and noble gas shorthand for Hydrogen
Electron Configuration of Lithium
Orbital filling for Lithium (s-block)
Electron Configuration of Beryllium
Orbital filling for Beryllium (s-block)
Helium on the Periodic Table
Full properties and periodic trends for Helium
Orbital Hybridization
See how atomic orbitals mix to form sp, sp2, and sp3 hybrids