Question

What produces light and all other electromagnetic waves?
charged particles
heated metals
radioactive samples
the photoelectric phenomena

Answer 1

All of the above. Charged particles like electrons and photons can produce light and other electromagnetic waves. Heated metals, such as in an incandescent light bulb, can also produce light through thermoluminescence. Radioactive samples can emit radiation that includes electromagnetic waves in the form of gamma rays. Finally, the photoelectric phenomena occurs when certain metals, when hit by photons of light, can emit electrons and produce light in the process.