The questions are attached, the answer to both is: undefined, i need a detailed response on how you got to the answer

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2