Hydrogen The element hydrogen, with one electron per neutral atom, is usually placed at the top of Group 1 of the periodic table because of its electron configuration. But hydrogen is not normally considered to be an alkali metal. Metallic hydrogen, which only exists at very high pressures, is known for its electrical and magnetic properties, not its chemical properties. Under typical conditions, pure hydrogen exists as a diatomic gas consisting of two atoms per molecule (H2); however, the alkali metals form diatomic molecules (such as dilithium, Li2) only at high temperatures, when they are in the gaseous state.Winter, Mark J. (1994) Chemical Bonding, Oxford University Press,
Hydrogen The element hydrogen with one electron per neutral atom is usually placed at the top of Group 1 of the periodic table because of its electron configuration But hydrogen is not normally considered to be an alkali metal Metallic hydrogen which only exists at very high pressures is known for its electrical and magnetic properties not its chemical properties Under typical conditions pure hydrogen exists as a diatomic gas consisting of two atoms per molecule (H2); however the alkali metals form diatomic molecules (such as dilithium Li2) only at high temperatures when they are in the gaseous stateWinter Mark J (1994) Chemical Bonding Oxford University Press