Alkali Metals

Alkali Metals

Enjoy these interesting alkali metals facts and properties. Learn what makes lithium, sodium, potassium, rubidium, caesium and francium different from other metals in the periodic table of elements.

Lithium (Li)

Atomic number 3

Under normal conditions lithium is the lightest of all metals. Lithium only appears naturally as part of a compound.

Sodium (Na)

Atomic number 11

Sodium is a silvery white metal that is soft enough to be cut with a knife at room temperature.

Potassium (K)

Atomic number 19

Potassium only occurs in nature as ionic salt. It is found as part of minerals and dissolved in sea water.

Rubidium (Rb)

Atomic number 37

Rubidium was discovered in 1861. It gives a reddish violet color when burned in a a flame.

Caesium (Cs)

Atomic number 55

Caesium has a melting point of 28 °C (83 °F), is one of only five metals that are liquid at or near room temperature (the others being mercury, francium, gallium and rubidium).

Francium (Fr)

Atomic number 87

Francium was the last element discovered in nature and it is extremely rare, scientists predict that only 20 to 30 grams of it exists on Earth.