Environmental problem that burning fossil fuels produces?
- produces pollutant gases, solid waste/ash/smoke
Why are telescopes that detect different types of EM waves used to observe the Universe?
- sources emit all different types of EM radiation/waves
What is red-shift?
- wavelength of light increases
Describe the big bang theory?
- explosion causes universe ro expand.
Explain how heat is transferred by the process of convection from the gas flame at the bottom of the oven to the potatoes at the top of the oven?
- air particles gain energy, air particles move faster, air expands, warm air raises.
One harmful effect that UV radiation has on skin?
What is meant by an energy source being renewable?
- replaced faster than it is used
Renewable energy sources used to generate electricity?
- wind, tides, waves, fall of water, biomass, geothermal.
What happens to the wasted energy?
- transferred to surroundings
What is a beta particle and from which part of an atom is a beta particle emitted?
- electron… from the nucleus
What is meant by isotopes?
- element with the same number of protons but different numbers of neutrons.
What is meant by radioactive?
- substance that give out radiation.
What is an alpha particle?
Why Plutonium-238 is unlikely to cause any harm if it is outside the body but is likely to kill if it is inside the body?
- outside the body alpha (particle) cannot penetrate into the body.
- Inside the body heat produced from decay kills cells.
Which type of EM waves has a lower frequency than microwaves?
What do all types of EM wave transfer from one place to another?
What effect will the absorbed microwaves have on the e.g. ball?
What is the difference between an analogue signal and a digital signal?
- digital is a signal that has only two sates (discrete values) whereas analogue is a signal that varies continuously.
How is the image produced by the Hubble telescope better than the image produced by the William Herschel telescope?
-
clear/ more detailed/ less distorted image. Give a reason;
- because no light pollution/ light is not scattered by the atmosphere
Advantage of sending information as a digital signal rather than as an analogue signal?
- better quality signal/ can be easily processed by computer.
Other use o microwaves?
- satellite communication/ cooking
What is the name of the process by which a nuclear fuel produces heat?
Explain how the heat released from a nuclear fuel is used to generate electricity in power stations?
- water heated to produce (high pressure) stem, steams turns turbine which drives generator
Why is the waste from a nuclear power station dangerous?
Why outside surface of the fridge is white and shiny?
- poor absorb of heat/ radiation, reflect heat/ radiation away from fridge-freer.
Explain how the gold-198 is used to find where the pollution is coming from?
- put sources into water at one point on bank, see if radiation is detected in polluted area.
