Find the minimum energy that a `gamma`-ray must have to give rise to an electron -positron pair.
`{:("Mass of electron",= 0.00055 am u,),("Mass of positron",= 0.00055 am u,):}`

What is the minimum energy which a gamma ray photon must possess in order to produce electron positron pair ?

Calculate the amount of energy set free by the annigilation of an electron and a positron. Given that mass of electron = 0.00055 amu and positron = 0.00055 amu.

What is the minimum energy released in the annhilation of an electron positron pair?

The rest mass energy of electron or positron is (in MeV )

Calculate the binding energy of helium nucleus (._(2)^(4)He) and express the quantity in MeV and J {:("Mass of helium nucleus",=,4.0028,am u,),("Mass of proton",=,1.00758,am u,),("Mass of neutron",=,1.00897,am u,):}

Calculate the binding energy of the lithium atom (._(3)^(7)Li) from the following data: {:("mass of proton",= 1.00759,am u,),("mass of neutron",= 1.00898,am u,),("mass of electron",= 0.00055,am u,),("mass of lithium atom",= 7.01818,am u,):}

The sun is believed to be getting its energy form the fusion of four protons to form a helium nucleus and a pair of positrons. Calculate the release of energy per fusion in MeV. Mass of proton=1.007825 a.m.u. , mass of positron =0.000549 a.m.u., mass of helium nucleus =4.002603 a.m.u. Take 1a.m.u. =931MeV.

gamma-rays radiation can be used to create electron-positron pair. In this process of pair production. gamma-rays energy cannot be less than.