AP EAPCET 07-Jul-2022 Shift 1 Paper

Generally, group 6,7,8 and 9 has low affinity towards hydrogen when they are in their normal oxidation states. This prevents the formation of metal hydrides. But chromium ( Cr) is an exception. The Cr absorb hydrogen in almost 1:1 stoichiometric quantity. During the formation of such compounds hydrogen atoms occupy the interstitial sites present in crystals of metals.