Covalent hydrides are all the other compounds of hydrogen wher hydrogen is covalently bonded- typiccally sharing an electron pair as in CH4 (methane) which could be called carbon tetrahydride although this is not a recognised name.The term hydride is usually applied to ionic compounds of hydrogen and metals of group 1A (alkali metals) and group 2A (alkaline earth metals) (notale exception Be) . In these hydrides,metal atoms form positive ion by losing valence electronsand hydrogen forms negative ion gaining that electron in order to complete its shell.