Heat from fuels is sometimes used to heat water and create steam. the steam expands, compared to liquid water, and may be used to push a piston or turn a generator. in this case, the heat from the fuel is being most directly. a. transformed into potential energy. b. used to warm the building. c. used to perform work.

C) Used to perform work

Explanation:

In this case, the heat from the fuel is transferred to the water and used as the energy necesary to evaporate the water and expand. The expansion energy is also transferred to move the piston. This energy used to move the piston is called work.

that's what i got you can count the number of atoms

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock