Nuclear Fission and Fusion

Question 1

Nuclear Fission

Answer 1

nuclear fission is the splitting up of big atomic nuclei

Question 2

Nuclear Fusion

Answer 2

the joining of small atomic nuclei

Question 3

nuclear fission- what happens in a nuclear reactor?

Answer 3

in a nuclear reactor a controlled chain reaction takes place in which nuclei split and and release in the form of heat
the heat is then used to heat water and turn a steam turbine

Question 4

what is the fuel that is usually split in a nuclear reactor

Answer 4

uranium-235
or
plutonium-239

Question 5

how do the chain reactions work in nuclear fission

Answer 5

if a slow moving neutron gets absorbed by a plutonium or uranium nucleus, the nucleus can split
each time a plutonium or uranium nucleus splits up, it splits out two or three neutrons which may hit another nucleus causing it to split, causing a chain reaction

Question 6

what happens in nuclear fusion

Answer 6

two light nuclei can combine to create a larger nucleus, this is called nuclear fission
fusion releases a lot of energy, for example all energy released in stars is by fusion, so fusion reactors are being developed to make electricity
fusion doesn’t leave behind radioactive waste
however fusion requires a huge amount of heat to work - 10 000 000 degrees C - and is very hard to achieve this
also it is really hard to build fusion reactors as in the heat they would usually be vaporised