Watch a Video:
Watch the video below and answer the following questions.
1. What happens to light when it passes from one medium to another?
2. What is refraction?
3. An object is only visible when it _____________________.
4. What is the refractive index?
5. Why can you still see the test tube in the beaker of water?
6. Why can you not see the test tube in the oil?
7. Why can you see the empty test tube in the large beaker of oil?