Can someone help me solve question 'a' please? Just need to know how you did it so I can do the rest.

What effect might melting sea ice have for people who live in coastal areas?

What are the similarities of physical and chemical change ?

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?