Alkali metal

The alkali metals are the series of elements in Group 1 (IUPAC style) of the periodic table, excluding hydrogen: that is, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). They are all highly reactive and are rarely found in elemental form in nature.

Related Topics:
Series - Elements - Group 1 - IUPAC - Periodic table - Hydrogen - Lithium - Sodium - Potassium - Rubidium - Caesium - Francium

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The alkali metals are silver-colored, soft, low-density metals, which react readily with halogens to form ionic salts, and with water to form strongly alkaline (basic) hydroxides. These elements all have one electron in their outermost shell, so the energetically preferred state of achieving a filled electron shell is to lose one electron to form a singly charged positive ion.

Related Topics:
Density - Metal - Halogen - Ionic salt - Water - Alkaline - (basic) - Hydroxide - Electron - Electron shell - Charged - Ion

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Hydrogen, with a solitary electron, is sometimes placed at the top of Group 1, but it is not an alkali metal; rather it exists naturally as a diatomic gas. Removal of its single electron requires considerably more energy than removal of the outer electron for the alkali metals. As in the halogens, only one additional electron is required to fill in the outermost shell of the hydrogen atom, so hydrogen can in some circumstances behave like a halogen, forming the negative hydride ion. Binary compounds of hydride with the alkali metals and some transition metals have been prepared.

Related Topics:
Hydrogen - Gas - Halogen - Hydride - Transition metal

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Under extremely high pressure, such as is found at the core of Jupiter, hydrogen does become metallic and behaves like an alkali metal, see metallic hydrogen.

Related Topics:
Pressure - Jupiter - Metallic hydrogen

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~