Objective 3.13

3.13
recall that the detrimental effects of excessive exposure of the human body to electromagnetic waves, including:
* microwaves: internal heaating of body tissue
* infrared: skin burns
* ultraviolet: damage to surface cells and blindness
* gamma rays: cancer, mutation

Objective 3.12

3.12
recall some of the uses of electromagnetic radiations, including:
* radio waves:broadcasting and communications
* microwaves: cooking and satellite transmissions
* infrared: heaters and night vision equipment
* visible light: optical fibres and photography
* ultraviolet: fluorescent lamps
* x-rays:observing the internal structure of objects and materials and medical applications
* gamma rays: sterilising food and medical equipment