What is a boundary?

What is the incident ray?

What angle is the angle of incident the same as?

What does refraction mean?

What is a converging lens?

What does the focal point mean?

What does the objective lens do?

What does the eye piece lens do?

What kind of telescope uses a concave mirror?

How did Ritter discover ultraviolet radiation?

What are microwaves used for?

What are the dangers of UV radiation

What is infrared used for?

What are the THREE types of ionising radiation?

What does ionising radiation cause atoms to do?