All of them are soluble salt.
First one dissociates into two ions.
The second one dissociates into 3 ions.
The third dissociate into 4 ions. therefore, Al(NO3)3
B because....................
Answer 2, because when you add salt to something, it cools faster (ex. When you add salt to an ice chest so that it stays cold) and it takes longer to boil (ex. When you boil salt out of ocean water so that its safe to drink) therefore, the more NaCl in the solution, the more it will exibit these properties
The region is located on an active oceanic plate
I believe it is "empirical formula"