What is the mass number of an atom with 5 protons and 7 neutrons

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.

The passing of heat through a material while the material itself stays in place. a. radiation b. conduction c. convection

Could someone . i have tried to solve myself but my calculation is off