Why does water have unique characteristics compared to other similar molecules

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

Ineed ! i have no clue how to do this problem.

What causes most sediment to wash or fall into a river