Why does Carbon dioxide () exist as a discrete gas molecule while Silicon dioxide () forms a giant 3 — p Block Elements Chemistry Question

💡 Solution & Explanation

Carbon, being a small period 2 element, easily forms strong $p\pi-p\pi$ double bonds with oxygen to form linear $O=C=O$ molecules. Silicon is too large for effective $p\pi-p\pi$ overlap, so it forms strong single bonds with four oxygens, creating a giant 3D network.