Whitch has a higher viscosity; cola or air?

Question

please tell why if possible!

Answer 1

Imagine sucking air through a straw or cola through a straw. It is much easier to suck air. Thus, it has a lower viscosity. A milkshake has even higher viscosity.
Now as to "why", that is more difficult. It is due to the greater intermolecular forces in cola as compared to air. Cola molecules like to stick together more than do air molecules. This is due to their size and their polar bonding.

Answer 2

Viscosity is the tendency of a fluid to resist flow. Air has an extremely low viscosity, so cola would have a higher viscosity compared to air.