Physics Two - Radiation and Life
Radiation and life :0
- Created by: jac
- Created on: 23-06-10 10:31
Light is an electro magnetic radiation
Light is a type of ELECTROMAGNETIC RADIATION - EM
Visible light (colours of the rainbow) is radiation our eyes can see
Radiation towards the red end of the rainbow is infa red radiation
The raiation towards the violet end is called ultra violet.
Radio
waves
Micro
waves
Infa
Red
Visible
Light
Ultra
Violet
X-Rays
Gamma
Rays
Frequency
Type of electromagnetic radiation
Typical useWavelength
highest
gamma radiation
killing cancer cells shortest X-rays medical images of bones
ultraviolet radiation
sunbeds
visible light
seeing infrared radiation optical fibre communication microwaves cooking
lowest
radio waves television signals longest
Photons
- Em transfers energy, this is through protons
- EM SOURCES EMIT THESE
- each proton carries a different amount of energy depending where it is on the
EM SPECTRUM - More energy if it towerds ultra violet and less if beyone infa red
Sources - Sun , radio , mobile phones etc....
Energy spreads out until it reaches a form of matter;;
Transmitted - keeps going through eg.glass
Rflected - bounces back eg.mirror These are called detectors
Absorbed - skin absorbs sun
- Energy given out is
TOTAL ENERGY = number of protons x energy per proton
- intensity of radiation is how much energy arrives at a sqaure metre per second
- Units of intensity measured in
W/m - Watts per square metre
- Intensity of of radiation beams decrease as it moves further from source as protons spread out so less hit you
Ionisation
- some em radiation cause ionisation - ultra violet , x - ray , gamma ray
- When aphoton hits an atom if it is ionising it will break the atom into bits called IONS
- If this happens to body cells it can damage important DNA
- it will cause mutations and cells may begin to constantly divide - causing cancer
- We all get exposed to uv radiation from sun which can damage skin cells causing sun burn
- or bad cases can cause skin cancer - You can protect by physical barriers like - Clothes - sunscreen
- When an X - Ray is taken - un investigated body parts are coverd with lead shields to absorb radiation thats unnnecary to certain parts.
Uses of EM radiation
- non ionising radiation when absorbed trandefers energy to molecules and atoms - Making them heat up
- If exposed to heat to long or a high amount - YOU BURN
- we use this to cook food
Microwave Radiation - if exposed to it water in body could heat up dangerously why microwave ovens have metal casesand glass doors to stop there protons reaching us.
Infa Red- tv, remotes , night vision cameras
Microwave - microwaves , mobile phones , satellite communication
Radio - Tv , radios transmisions radar
Photosynthesis
.
Greenhouse Effect
.
Ozone Layer
- ozone is an oxygen molecule conatain three oxygen atoms - 03
- Ozone happens naturally at a certain height - making the ozone layer around earth
Climate Change
- Green house effect of co2 naturally heating earth works to well as we are flooding our atmosphere with co2 and ch4. OVER HEATIN - GLOBAL WARMING
Consequences
- Ice melting - causing floods, meaning land will get wet not good enough to grow crop
- Or over heating making longer droughts, and hurricanes - To dry for crop
Related discussions on The Student Room
- AQA GCSE Combined Science: Trilogy - Physics Paper 1 (Higher) 8464/P/1H [Exam Chat] »
- AQA GCSE Physics Paper 1 (Higher Tier triple) 8463/1H - 25th May 2023 [Exam Chat] »
- Hard biology question »
- GCSE AQA Physics Paper 1 and 2 Revision and Study Chat »
- Physice revision? »
- I am a diagnostic radiographer - AMA »
- Should I do computer science or physics at uni? »
- A level physics nuclear question »
- GCSE revision journey »
- Edexcel A Level Physics Paper 3: 9PH0 03 - 15th June 2023 [Exam Chat] »
Comments
No comments have yet been made