$\begin {array}{1,1}(a)\;2.609A^{\large\circ},16.199g/cm^3\\(b)\;1.303A^{\large\circ},16.99g/cm^3\\(c)\;2.609A^{\large\circ},7.200g/cm^3\\(d)\;1.303A^{\large\circ},6.198g/cm^3\end {array}$