da Covey Tan mancano 12 anni
206
Più simili a questo
when a preceedding compression left a decompression wave in it's wake and causes a rarefaction to occur.
This causes the air particles to be pulled apart.
When the a vibration in the air causes the air to be pressed together
This causes the air particles to be pressed together.
Uses of Gamma Rays
1. Kill cancer cells.
2. kill harmful bacteria in food.
3. Sterilise surgical instruments.
Uses of X-ray
1. Look into a person's body to discover their illnesses or injuries.
2. Check the contains of luggages in immigration offices and airports.
Uses of Ultraviolet Ray
1. Detecting forged bank notes by fluorescence.
2. Fluorescent lights.
Uses of Visible Light
1. Enabling us to see.
Uses of Infrared
1. Optical fibre.
2. Burglar alarms.
3. Remote controls for television sets and DVD player.
Uses of Microwaves
1. Transmit signals such as mobile phone calls.
2. Heat up food particles.
Uses of Radio Waves
Transmit television and radio programmes.
Gamma ray is ionising radiation
It is used to treat tumour cells. However it could damage the surrounding cells and tissues which absorb the rays
Ionisation is the process of ion formation
Ultra-violet rays are highly energetic
Able to ionise atoms which can be harmful to living tissues
Under excessive expore to UV rays can cause sunburn and skin cancer
When water absorbs micorwaves, they are warmed up
The burning of coal gives out infrared radiation as heat to the surrounding