Q. Show  the Hydrides of Boron and Aluminium?

Boron forms a series of volatile hydrides which resemble in some respects, e.g., volatility and covalent nature, the hydrides of carbon and silicon. The boron hydrides are generally called boranes by analogy with the alkanes and silanes. In view of its trivalency, boron is expected to form a simple hydride BH,, but it is unstable. The simplest stable hydride of boron is diborane B₂H₆. There are about dozen well characterised boron's which correspond to the following two stoichiometries: 

i) B_nH_n+4 : B₂H₆, B₅H₉, B₆H₁₀, BS₈H₁₂, B₁₀H₁₄, B₁₈H₂₂ and iso-B₁,H2,

ii) B_nH_n+6: B₄H₁₀ B₅H₁₁, B₆H₁₂, BS₉H₁₅, B₁₀H₁₆, B

Boranes are usually named by indicating the number of B atoms with a prefix and the number of hydrogen atoms by an arabic number in parenthesis. For example, B_4,H₁₀, is named as tetraborane(l0) and B,H,, as nonaborane(l5). The hydride, B₂H₆ is simply called diborane as the compound of stoichiometry B₂H₈ is not known.