If 7.84 × 107 j of energy is released from a fusion reaction, what amount of mass in kilograms would be lost? recall that c = 3 × 108 m/s.

Which statements describe polyatomic ions? check all that apply. polyatomic ions have many charges. polyatomic ions have one overall charge. polyatomic ions repel other ions to form ionic bonds. polyatomic ions attract other ions to form ionic bonds. polyatomic ions are made up of only one type of atom. polyatomic ions are made up of two or more types of atoms.

The answer for #3 is c but i don't know why

What layer of the atmosphere is directly above the troposphere?