What kind of bonding is involved in carbon dioxide and silicon dioxide?

This actually illustrates an interesting phenomenon with respect to $\text{molecular}$, and $\text{non-molecular bonding.}$
Now carbon dioxide is molecular (and we are exhaling it now!), and the normal Lewis structure is $O = C = O$. The central carbon is $\text{sp-hybridized}$; the terminal oxygens are $s {p}^{2} - \text{hybridized}$.
On t'other hand, $S i {O}_{2}$ is NON-MOLECULAR...with infinite $S i - O - S i - O$ bridges... The third row silicon atom is LESS capable of participating in $p \pi - p \pi$ multiple bonding...and here we got a giant covalent structure rather than discrete molecules.