Alkali metals6 elements · group 1

The alkali metals are the elements of group 1 (except hydrogen): lithium, sodium, potassium, rubidium, caesium and francium. Each has a single electron in its outer shell, which it gives away very easily, so they are the most reactive metals of all. They are soft enough to cut with a knife, have low melting points and react vigorously with water to form hydrogen gas and strongly alkaline hydroxides — which is where the name comes from. Reactivity increases down the group.

# Properties of alkali metals

One valence electron (ns¹)
Soft, silvery and low density — lithium, sodium and potassium float on water
React with water to form hydrogen and an alkaline solution
Stored under oil to keep air and moisture away
Reactivity increases down the group

# List of alkali metals

#	Symbol	Element	Atomic mass	Electron configuration	State at 25 °C	Melting point
3	Li	Lithium	6.941	[He] 2s¹	solid	453.69 K
11	Na	Sodium	22.99	[Ne] 3s¹	solid	370.87 K
19	K	Potassium	39.098	[Ar] 4s¹	solid	336.53 K
37	Rb	Rubidium	85.468	[Kr] 5s¹	solid	312.46 K
55	Cs	Caesium	132.91	[Xe] 6s¹	solid	301.59 K
87	Fr	Francium	223	[Rn] 7s¹	solid	300 K

# Alkali metals FAQ

Which elements are alkali metals?

There are 6 alkali metals in this table: Lithium, Sodium, Potassium, Rubidium, Caesium, Francium.

Where are the alkali metals on the periodic table?

The alkali metals are found in group 1, the far-left column (hydrogen sits above them but is not an alkali metal).

What are the properties of alkali metals?

One valence electron (ns¹); Soft, silvery and low density — lithium, sodium and potassium float on water; React with water to form hydrogen and an alkaline solution; Stored under oil to keep air and moisture away; Reactivity increases down the group.

# Other element categories

●Alkaline earth metals ●Transition metals ●Post-transition metals ●Metalloids ●Reactive nonmetals ●Halogens ●Noble gases ●Lanthanides ●Actinides