A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming (a) Identify A, B and C (b) To which Group of Periodic Table does A belong?

(a) Identification of A, B, and C

(1) A is Carbon$\left(\mathrm{C}\right)$. Carbon is an important constituent of our food as compounds of carbon are present in the food that we eat, the clothes that we wear etc.

(2) B is Carbon monoxide$\left(\mathrm{CO}\right)$.

• Carbon monoxide is a colourless and odourless gas that is produced by the incomplete combustion of materials containing carbon.
• Carbon monoxide poisoning can result in brain damage and even death as it has more affinity to combine with haemoglobin than Oxygen $\left({\mathrm{O}}_2\right)$

(3) C is Carbon dioxide $\left({\mathrm{CO}}_2\right)$.

• Carbon dioxide is a major contributor to global warming.
• Global warming: It is the gradual increase in the earth’s temperature generally due to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.

(b) Group of element A in the periodic table

• Electronic configuration of Carbon = $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^2$
• As the last electron enters in p-subshell, so carbon is a p-block element.
• For p-block elements, Group number= 12+ Number of electrons in p-subshell
• Therefore, Group number= 12+ 2= 14
• Hence, carbon belongs to Group 14.