Questions

We know that All compounds are molecules, but not all molecules are compounds.

Water is a molecule because it is made from atoms that have been chemically combined. It is also a compound because the atoms that make water are not all the same - some are oxygen and some are hydrogen.

Hence, Water is a molecule and a compound.

Tropical grasslands, or savannas, are also the homes of primates in Africa and Asia; no savanna-living primates exist in South America. Tropical grasslands comprise a mixture of trees and grasses, the proportion of trees to grass varying directly with the rainfall.

Both the floor and the carpet have the same temperature as both are exposed to the same atmosphere. But the former conducts away the heat from the feet better than the carpet as the latter is a non-conductor. So the feet losing more heat, the floor appears cooler to the feet.

The annual percentage rate (APR) on a credit card determines the amount of interest you are charged on credit card purchases.

Iteration means doing something again and again, repeatedly,... 

Hence, looping is a process of repeating a method and so it is similar in meaning to Iteration.