Question

Why is silicon dioxide a solid at room temperature and why is $ C{{O}_{2}} $ a gas?

Answer 1

Hint: A chemical relationship involving the sharing of electron pairs between atoms is known as a covalent bond. Shared pairs or bonding pairs are the stable balance of attractive and repulsive forces between atoms when they share electrons, while covalent bonding is the stable balance of attractive and repulsive forces between atoms when they share electrons. The sharing of electrons allows each atom in multiple molecules to achieve the equivalent of a complete valence shell, resulting in a stable electronic state. Covalent bonds are far more frequent in organic chemistry than ionic ones.

Complete answer:
Carbon dioxide is a colourless gas with a density that is around 60% that of dry air. A carbon atom is covalently doubly linked to two oxygen atoms to form carbon dioxide. It is found as a trace gas in the Earth's atmosphere.
Silicon dioxide, often known as silica, is a silicon oxide with the chemical formula $ Si{{O}_{2}} $ that is found in nature as quartz and in a variety of living creatures.
Because of what are known as "van der Waals forces" or "London forces," each molecule in $ C{{O}_{2}} $ (O=C=O) is attracted to neighbouring molecules. Van der Waals forces are a weak type of intermolecular interaction that attracts transient and induced dipoles.
Carbon dioxide melts at slightly over -56.6 degrees Celsius because Van der Waals forces may be broken with minimal energy.
Every silicon atom in $ Si{{O}_{2}} $ is covalently linked to four oxygen atoms. Every oxygen atom has two silicon atoms linked to it. This results in a massive tetrahedral structure, similar to that of a diamond. The lattice is extremely strong since all of the atoms are linked by covalent bonds. The melting point of $ Si{{O}_{2}} $ is 1713 degrees Celsius, which proves this.
Hence silicon dioxide is a solid at room temperature.

Note:
Between atoms with identical electronegativities, covalency is highest. Covalent bonding does not necessitate that the two atoms be of the same element, just that their electronegativity be similar. Delocalized covalent bonding is defined as the sharing of electrons between more than two atoms.