CH3NH2 can only have as many hydrogen bonds as hydrogen bonding sites in the molecule. CH3NH2 has two N−H bonds and a lone pair of electrons on the nitrogen atom. Therefore, CH3NH2 can form three hydrogen bonds with water.
The correct answer is Reference Point
Isotonic refers to a solution having the same water potential as compared to another solutions such that there is no net movement of water molecules across a membrane when these two solutions are put together
Answer:

Explanation:
When an atom has 2 or more isotopes, the average atomic mass (aam) depends on the mass of each isotope (mi) and the percentual abundance in nature of each isotope (abi). The average atomic mass can be calculated using the following expression:
