It is a white, odourless solid which slowly decomposes into its elements at room temperature; despite this it is the most stable of the binary first row transition metal hydrides.

New evidence suggests that in zinc(II) hydride, elements form a one-dimensional network (polymer), being connected by covalent bonds.

[8] It is readily oxidised and is sensitive to both air and moisture; being hydrolysed slowly by water but violently by aqueous acids,[3] which indicates possible passivation via the formation of a surface layer of ZnO.

The reaction of excited zinc atoms with molecular hydrogen in the gas phase was studied by Breckenridge et al using laserpump-probe techniques.

Quantum chemical calculations predict the molecular form to exist in a doubly hydrogen-bridged, dimeric groundstate, with little or no formational energy barrier.