inc ▁is ▁bl u ish - white ▁and ▁l ustr ous , ▁though ▁most ▁common ▁commercial ▁gr ades ▁of ▁the ▁metal ▁have ▁a ▁d ull ▁finish . ▁Z inc ▁is ▁also ▁referred ▁to ▁in ▁n ons cient ific ▁context s ▁as ▁spel ter . ▁Cad m ium ▁is ▁soft , ▁m alle able , ▁du ct ile , ▁and ▁with ▁a ▁bl u ish - white ▁color . ▁ ▁Mercur y ▁is ▁a ▁liquid , ▁heavy , ▁sil very - white ▁metal . ▁It ▁is ▁the ▁only ▁common ▁liquid ▁metal ▁at ▁ordinary ▁temper atures , ▁and ▁as ▁compared ▁to ▁other ▁met als , ▁it ▁is ▁a ▁poor ▁conduct or ▁of ▁heat , ▁but ▁a ▁fair ▁conduct or ▁of ▁electric ity . ▁ ▁The ▁table ▁below ▁is ▁a ▁summary ▁of ▁the ▁key ▁physical ▁properties ▁of ▁the ▁group ▁ 1 2 ▁elements . ▁Very ▁little ▁is ▁known ▁about ▁cop ern ici um , ▁and ▁none ▁of ▁its ▁physical ▁properties ▁have ▁been ▁confirmed ▁except ▁for ▁its ▁bo iling ▁point ▁( t ent ative ). ▁ ▁Z inc ▁is ▁somewhat ▁less ▁dense ▁than ▁iron ▁and ▁has ▁a ▁hex ag onal ▁cry stal ▁structure . ▁The ▁metal ▁is ▁hard ▁and ▁brit t le ▁at ▁most ▁temper atures ▁but ▁becomes ▁m alle able ▁between ▁ 1 0 0 ▁and ▁ 1 5 0   ° C . ▁A bove ▁ 2 1 0   ° C , ▁the ▁metal ▁becomes ▁brit t le ▁again ▁and ▁can ▁be ▁pul ver ized ▁by ▁be ating . ▁Z inc ▁is ▁a ▁fair