8.3 - fossil fuels & nuclear energy

Question 1

fossil fuel

Answer 1

a hydrocarbon containing material formed naturally in the earths crust from the remains of dead plant and animals

Question 2

three main fossil fuels

Answer 2

coal
crude oil
natural gas

Question 3

why burn fossil fuels

Answer 3

to provide heat
this heat can be used to:
- provide heat directly, eg for cooking
- to power engines (the internal combustion in cars)
- to generate electricity

Question 4

how long does it take fossil fuels to form

Answer 4

millions of years

Question 5

pros of fossil fuels

Answer 5

relatively cheap

can be used in any conditions (doesn’t need wind or sunshine to work)

much of our current infrastructure is designed to run using fossil fuels (eg cars)

Question 6

cons of fossil fuels

Answer 6

they’re a limited resource, so will run out one day

they produce carbon dioxide when burned - greenhouse gas - contributes to global warming

sometimes produce toxic gases when burnt - such as sulfur dioxide and carbon monoxide

Question 7

how is nuclear energy obtained

Answer 7

via nuclear reactions such as nuclear fission reactions in nuclear power stations

this energy can be used to when rate electricity which can then be transmitted to homes and factories

Question 8

pros of nuclear energy

Answer 8

does not produce any pollutants

can be used in any conditions

very unlikely to run out for a very long time

Question 9

cons of nuclear energy

Answer 9

finite resource

nuclear power stations produce radioactive waste which remains harmful for thousands of years

quite expensive

very small chance of nuclear meltdown - would release large amounts of radioactive material into the environment

long start up time (nuclear power plants take many years to build)