Solid CO2 (dry ice) forms a molecular crystal that sublimes at -78oC. SiO2 forms a network solid that melts at about 1200oC. Which of the following accounts for this striking difference in properties?
Unlike C, Si does not normally exist in the +4 oxidation state.
Si is more electronegative than C.
Si is a stronger Lewis base than C.
Unlike C, Si uses d-orbitals in bonding.
Unlike C, Si cannot make multiple bonds.