Lithium (Li) - Element 3 | Properties & Electron Configuration
What is Lithium?
Lithium (Li) is element 3, a alkali metal in period 2, group 1. Its electron configuration is 1s² 2s¹.
| Atomic Number | 3 |
| Symbol | Li |
| Atomic Mass | 6.941 u |
| Category | Alkali Metal |
| Period | 2 |
| Group | 1 |
| Block | s |
| Electron Configuration | 1s² 2s¹ |
| Short Config | [He] 2s¹ |
| Electronegativity | 0.98 |
| Atomic Radius | 145 pm |
| Ionization Energy | 520 kJ/mol |
| Electron Affinity | 60 kJ/mol |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Lithium is 1s² 2s¹. In noble gas shorthand, this is written as [He] 2s¹.
Lithium is a s-block element in group 1, period 2.
Periodic Trends
Electronegativity: Lithium has a Pauling electronegativity of 0.98. Within group 1, electronegativity generally decreases down the group.
Atomic Radius: 145 pm. Across period 2, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 520 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Lithium on the Interactive Periodic TableRelated Topics
Hydrogen (H)
Properties of Hydrogen - same group as Lithium
Sodium (Na)
Properties of Sodium - same group as Lithium
Potassium (K)
Properties of Potassium - same group as Lithium
Beryllium (Be)
Properties of Beryllium - same period as Lithium
Boron (B)
Properties of Boron - same period as Lithium
Carbon (C)
Properties of Carbon - same period as Lithium