Pages in this set

Page 1

Preview of page 1
OCR (Gateway) P4 revision notes - Radiation for life.

GENERATING STATIC ELECTRICITY:
Insulating materials can become electrically charged if rubbed with another insulating
material.
Electrons transfer from one material to another, one material will gain a positive charge and
the other will gain a negative charge due to the transfer…

Page 2

Preview of page 2
USING STATIC IN EVERYDAY LIFE
Photocopiers:
Image of page to be copied is projected onto a positively charged plate
Light causes charge to leak away, leaving electrostatic impression of the page
Charged impression on plate attracts tiny specks of black powder, transfers from
plate to paper
Heat fixes final image…

Page 3

Preview of page 3
DOUBLE INSULATION:
Appliances with outer metal cases have an earth wire, they are earthed.
An earthed conductor cannot become live.
Some have cases are made of insulators, don't have an earth wire but still have a fuse.

EARTHING:
Electrical appliances with outer metal cases are earthed to protect the appliance…

Page 4

Preview of page 4
PARTICLE MOTION IN WAVES:
All waves transfer energy from one point to another, without transferring any particles of
matter.
Two types of waves:
Longitudinal Waves- each particle move backwards and forwards about its normal
position , same plane as the direction of wave movement
Transverse waves- each particle moves up…

Page 5

Preview of page 5
TRACERS:
Tracers are small amounts of radioactive materials which can be swallowed or injected into a
patient.
Given time to spread through the body, whilst progress is followed using external radiation
detector.
Radioactive material must emit either gamma or beta radiation, both pass through skin, able to
be detected.

RADIOACTIVITY:…

Page 6

Preview of page 6
BACKGROUND RADIATION:
Occurs naturally in our environment and is all round us.
Most is released by:
Radioactive substances in soil and rocks.
Cosmic rays from outer space.
Some background radiation comes from man-made sources and waste products.
Industry and hospitals both contribute to background radiation levels.

TRACERS:
Radioisotopes are used…

Page 7

Preview of page 7
FISSION:
Nuclear fission is the process which heat energy is given out in a nuclear reactor.
Decay of uranium can be a chain reaction.
Uranium nucleus absorbs a single neutron, becomes radioactive and splits, releasing heat energy
& more neutrons.
These neutrons cause more uranium nuclei to split, chain reaction…

Comments

No comments have yet been made

Similar Science resources:

See all Science resources »