6. Al, Ga and In form cyanides with composition M(CN), and M coordination 6. The corresponding cyanide of TI (thallium) has a stoichiometry TI(CN)2 with two chemically different kinds of thallium. Explain why and speculate on the structure of the compound [hint: structure similar to Zn(CN)2l 7. The most common chlorides of C, Si, Ge and Sn are covalent and have compositions MCl. The most stable chloride of Pb is ionic with composition PbCl2. Explain the difference in stability (chemical behavior) among the latter and the other group IV chlorides.