1. Gamma rays, like visible light, are a form of electromagnetic radiation. Gamma rays have a higher frequency than visible light and carry more energy. But since gamma radiation is still electromagnetic radiation, it travels at the same speed as visible light. Hence the answer is d, none of these.
2. We see things because they reflect light. If an object absorbs all visible light except green, which it reflects, it is the reflected green light that allows you to see the object, so it appears green. When incoming light strikes the surface of an object, some frequencies are absorbed and others just set the atoms vibrating, causing them to emit reflected waves. The answer is c.
3. When an object absorbs all light, it reflects none and transmits none, so it appears black and opaque. The energy in the waves is transformed into heat. If you put a black object outside on a sunny day, it will absorb all of the sun's light and get very, very hot. That's why it's better to wear light colors on hot days than dark colors. The answer is d, all of these.
