P4: FISSION AND FUSION

Question 1

What is nuclear fission?

Answer 1

the splitting of a large atomic nucleus into smaller nuclei:
-in a nuclear reactor a neutron is absorbed into a nucleus (typically uranium-235). This causes the nucleus to become uranium-236, which is violently unstable
-the entire nucleus splits into two large fragments called ‘daughter nuclei’
-in addition to the ‘daughter nuclei’, 2/3 neutrons also explode out of the fission reaction and these can collide with other uranium nuclei to cause further fission reactions. This is known as a chain reaction

Question 2

What is nuclear fusion?

Answer 2

nuclear fusion is when two small, light nuclei join together to make one heavy nucleus
(fusion reactions occur in stars where two hydrogen nuclei fuse together under high temps and pressure to form a nucleus of a helium isotope)