Question

Solid carbon dioxide, $C{{O}_{2}}$ , is similar to solid iodine, ${{I}_{2}}$ in its structure and properties. Carbon is in Group 14. Silica, $Si{{O}_{2}}$ , is a Group 14 compound. Which statement about solid $C{{O}_{2}}$ and solid $Si{{O}_{2}}$ is correct?
(a) Both sides exist in a lattice structure
(b) Both solids have a simple molecular structure
(c) Both solids have atoms joined by single covalent bonds
(d) Both solids change spontaneously to gas at STP

Answer 1

A unit cell is the smallest repeating unit in the crystal lattice, it is the building block of a crystal like the cell which is the building block of the human body.

Complete answer:
To solve this question, we will check every option:
For option (A), we know that the solid iodine has a simple molecular lattice and since both of them i.e. solid carbon dioxide and solid iodine have similar structure and properties, it means that that carbon dioxide can also have lattice structure.
For option (B), this option is incorrect as we know that the structure of solid $Si{{O}_{2}}$ is similar to diamond which means that it has a giant covalent structure.
For option (C), this option is also incorrect as $Si{{O}_{2}}$ have four single bonds whereas carbon dioxide has two double bonds and is linear in structure.
For option (D), this option is also incorrect since at STP $Si{{O}_{2}}$ is a solid and this will not change into gas spontaneously.
Hence, the correct answer is option, ‘(a) Both sides exist in a lattice structure’.

Note: The chemical symbol is used to represent an atom or an element. The chemical symbol of an element usually consists of one or two letters from the Latin alphabet and the first letter is always capital. There are many sources from which the symbols are derived, it includes Greek name of an element or German name etc.