Atomic number 11
Sodium
Alkali metal
In the real world
Quick facts
- Atomic mass
- 22.990
- Group
- 1
- Period
- 3
- State (STP)
- solid
- Electronegativity
- 0.93
- Common ox. states
- +1
Properties
Electron configuration
[Ne] 3s¹
- Ionization energy
- 495.8 kJ/mol
- Electron affinity
- 52.8 kJ/mol
- Melting point
- 370.94 K (97.8 °C)
- Boiling point
- 1156.09 K (882.9 °C)
How dangerous is it?
3/5 · Hazardous
A soft silvery metal that fizzes and catches fire on water. Bonded to chlorine, though, the same element becomes ordinary table salt.
- FlammableImmediate
The heat of the water reaction ignites the hydrogen, so it burns with a yellow flame.
Never quenched with water; a sodium fire is covered with dry sand.
- ReactiveImmediate
It reacts vigorously with water, releasing flammable hydrogen and a lot of heat.
Stored under oil so air and moisture cannot reach it; cut and handled dry.
How it bonds
Sodium loses its single 3s electron easily to form Na⁺. It is the textbook alkali metal - bonds ionically with halogens (NaCl, NaF), oxide-formers (Na₂O), and acids (NaOH). The +1 ion is so stable in water that you almost never see anything else.
Where you meet it
- Periodic Quest challengeunlock card
