Nuclear fission and Nuclear fusion,DENSITY

Nuclear fission and Nuclear fusion

• There are two fissionable substances in common use

 in nuclear reactors, uranium 235 and plutonium 239.

• Nuclear fission is the splitting of an atomic nucleus.

• For fission to occur the uranium 235 or plutonium 239

 nucleus must first absorb a neutron:









     neutron







• The nucleus undergoing fission splits into two smaller

 nuclei and 2 or 3 neutrons and energy is released.

• The neutrons may go on to start a chain reaction, AS ABOVE.

• Nuclear fusion is the joining of two nuclei to form a larger one.

• Nuclear fusion is the process by which energy is released in stars.

. DENSITY

•  Density of an object = its mass divided by its volume,     

 Density  =  mass  /  volume                                                                       ρ =  m  / V                                      

      (kg/m3)      (kg)         (m3)

• You should be able to describe an experiment to measure the density of an object

  involving measurements of its mass, and its volume.