Whats the chemical formula for octahydrate? please explain how you got your answer <3

Asolid that forms and separates from a liquid mixture is called

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it