Question

Nuclear fission and nuclear fusion are both energy releasing processes.

                  One of these is currently of practical use on earth. Which one is it?

                  Why is the other of these not currently of practical use on earth?

Answer 1

Fission process is currently of practical use. We produce electricity by suing reactors which use fissionable materials like Uranium and use process of Fission

The other process which is not of practical use is Fusion.

For the Fusion reaction to start we need high temperatures which is not possible to obtain by normal fuels. Only Atomic bombs which are high energy reactions can give such temperatures. Once fusion starts with when such high temperature is given the fusion reaction gives very high energy ( compared to fission) . Such high energy cannot be controlled by materials we develop. Hence there are two main issues based on which fusion is not of pratcial use on earth (1) Need of very high temperature which is tougher       (2) Need proper materials which can withstand high energy