Question

which of the following could comprised of one atom A.carbon B.salt C.air​

Answer 1

Carbon is Carbon so it's just one atom.
Air is mostly O2, N2, H2O and ....
Salt is NaCl and not one atom ;)

Answer 2

Answer:

Carbon

Step-by-step explanation:

Carbon usually exist as single Carbon atoms. Salt consists of Sodium and Chlorine stoms and air is a mixture of gases so it consists of many atoms