Idk about 1, but for 2a: saturated means that all carbons have the maximum amount of hydrogens attached to them, and unsaturated means that they don’t. Only alkanes are saturated because they have all single bonds, so they have the max amt of hydrogens bonded to the carbons. 2b: saturated: butane, octane, methane. Unsaturated: ethene, butene.
The attraction of like water molecules to each other is called cohension
I think it’s B not quite sure ! Sorry