Potassium (K) - Element 19 | Properties & Electron Configuration
What is Potassium?
Potassium (K) is element 19, a alkali metal in period 4, group 1. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹.
| Atomic Number | 19 |
| Symbol | K |
| Atomic Mass | 39.098 u |
| Category | Alkali Metal |
| Period | 4 |
| Group | 1 |
| Block | s |
| Electron Configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ |
| Short Config | [Ar] 4s¹ |
| Electronegativity | 0.82 |
| Atomic Radius | 220 pm |
| Ionization Energy | 419 kJ/mol |
| Electron Affinity | 48 kJ/mol |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Potassium is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹. In noble gas shorthand, this is written as [Ar] 4s¹.
Potassium is a s-block element in group 1, period 4.
Periodic Trends
Electronegativity: Potassium has a Pauling electronegativity of 0.82. Within group 1, electronegativity generally decreases down the group.
Atomic Radius: 220 pm. Across period 4, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 419 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 Potassium on the Interactive Periodic TableRelated Topics
Hydrogen (H)
Properties of Hydrogen - same group as Potassium
Lithium (Li)
Properties of Lithium - same group as Potassium
Sodium (Na)
Properties of Sodium - same group as Potassium
Calcium (Ca)
Properties of Calcium - same period as Potassium
Scandium (Sc)
Properties of Scandium - same period as Potassium
Titanium (Ti)
Properties of Titanium - same period as Potassium