Question

The non-metal which exhibits yellow colour is:
A. silicon
B. phosphorus
C. Sulphur
D. carbon

Answer 1

Hint: Non-metals are electronegative and form bonds by electron sharing. From left to right of a row non- metallic character increases. And top to bottom of group non-metallic character decreases. Colour of a nonmetallic element is not a common property of non-metals.

Complete answer:
Among them sulfur possesses a yellow colour. Sulfur is an octa atomic molecule, where eight sulfur forms a crown like structure. Besides this there are so many allotropes of sulfur are present like, \[{S_6},{S_4}\] etc.

Therefore, the correct option is C.

Additional information:
In case of sulfur the reason for formation of octa atomic molecules is that, due to the large size of sulfur it cannot form \[p\pi - p\pi \] double bond. Due to this reason it forms \[{S_8}\] by sigma bonding. On the other hand, with the same group element oxygen due to small size it can form \[p\pi - p\pi \] double bond and form dioxygen. This kind of similar concept is also observed between nitrogen and phosphorus. Where nitrogen is diatomic as it can form \[p\pi - p\pi \] bond but phosphorus forms \[{P_4}\].

Note: In case of carbon, due to the high bond energy of carbon-carbon bond, it can form long chain compounds. It can form so many compounds as it can make bonds with four other atoms by covalent bond, this is because of its small size and electronegativity. This property is called catenation.