Electron Configuration of Lithium (Li)
What is the electron configuration of Lithium?
The electron configuration of Lithium (Li, Z=3) is 1s² 2s¹. In noble gas shorthand: [He] 2s¹. It has 1 unpaired electron(s) and is a s-block element.
| Symbol | Li |
| Atomic Number | 3 |
| Full Electron Configuration | 1s² 2s¹ |
| Noble Gas Shorthand | [He] 2s¹ |
| Block | s |
| Period | 2 |
| Group | 1 |
| Unpaired Electrons | 1 |
| Exception? | No |
Orbital Filling Order
Following the aufbau principle, the 3 electrons in Lithium fill orbitals in order of increasing energy: 1s (2 electrons), then 2s (1 electron).
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
The inner electrons of Lithium match the configuration of He. This allows us to abbreviate the configuration as [He] 2s¹, where [He] represents the filled core and the remaining entries show the valence electrons.
Valence Electrons
The valence shell of Lithium contains 1 electron in the 2s subshell. These outermost electrons determine Lithium's chemical reactivity, bonding behavior, and position in the periodic table as a s-block element in period 2.
Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.
Explore Lithium in the Electron Configuration ExplorerRelated Topics
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Electron Configuration of Neon
Orbital filling and noble gas shorthand for Neon
Electron Configuration of Hydrogen
Orbital filling for Hydrogen (s-block)
Electron Configuration of Helium
Orbital filling for Helium (s-block)
Lithium on the Periodic Table
Full properties and periodic trends for Lithium
Orbital Hybridization
See how atomic orbitals mix to form sp, sp2, and sp3 hybrids