Hydrogen
1.0 Basic Information
2.0 Atomic and Physical Properties of Hydrogen (reference: NCERT)
3.0 Dihydrogen
4.0 Physical Properties
5.0 Chemical Properties
6.0 Uses of Dihydrogen
7.0 Compounds of Hydrogen
8.0 Hard and Soft Water
9.0 Hydrogen Peroxide
10.0 Volume strength of Hydrogen Peroxide
7.1 Hydrides
Binary compounds of hydrogen with metals, non-metals and metalloids are called hydrides.
If $‘E’$ is the symbol of an element then hydride can be expressed as $EH_x$ (eg. $MgH_2$). Depending upon the physical and chemical properties, the hydrides are catagorised as
1. Saline/Ionic/Saltlike Hydrides: Hydrogen combines mostly with $s$-block metals, these hydrides are denser than the corresponding metals. In molten state, these hydrides are electrically conducting. e.g. $LiH$, $CaH_2$ (except $BeH_2$ and $MgH_2$).
2. Metallic/Intertitial Hydrides: Hydrogen combines with $d$-block and $f$-block elements. e.g. $ScH_2$ and $LaH_2$.
3. Molecular/Covalent Hydrides: Hydrogen combines with $p$-block elements (except $Te$) and $s$-block $BeH_2$ and $MgH_2$.
Note:
1. Molecular Hydrides are further divided as – electron deficient (e.g. $B_2H_6$), electron precise (e.g. $CH_4$) and electron rich (e.g. $NH_3$).
2. The elements of group $7$, $8$, $9$ do not form hydrides, this is known as Hydride Gap.
