A neutron breaks into a photon , an electron and antineutrino . Calculate the energy released in this process in MeV. Given : mass of electron , mass of proton , mass of neutron .
According to energy-mass relation, the energy released is
= 0.731 MeV.
The isotopes occur in nature in the ratio 140 : 1. Assuming that at the time of earth’s formation they were present in equal ratio, make an estimation of the age of the earth. The half-lives of respectively.
A radioactive isotope X has a half-life of 3 seconds. At t = 0 second, a given sample of this isotope X contains 8000 atoms. Calculate the number of decays per second in the sample at t = t1 second.
A radioactive element of atomic weight 99 has a half-life of 6 hours. Find the activity in a solution containing 1 gram of the element in the beginning. The Avogadro’s number is .
In an ore containing uranium, the ratio of nuclei is 3. Calculate the age of the ore, assuming that all the lead present in the ore is the final stable product of . Take the half-life of .
The mean lives of a radioactive substance are 1620 years and 405 years for-emission and -emission respectively. Find out the time during which three-fourth of a sample will decay if it is decaying both by -emission and-emission simultaneously.
Calculate the energy in joule equivalent to the mass of one proton. The mass of proton is 1.00728 u. Express the energy in kilowatt-hour also.
An electron-positron pair is produced by the materialization of a gamma-ray photon of 2.26 MeV. How much kinetic energy is imparted to each of the charged particle? The rest mass of elector is and the speed of light is . Take .
An electron and its antiparticle are annihilated after collision. How much energy will be obtained? What will be the wavelength of the emitted radiation (energy)? (Mass of electron , speed of light and Planck’s constant )
A 1-MeV positron collides head-on with a 1-MeV electron and they are annihilated, producing -rays. Compute total energy of the resulting -rays and their wavelength.Given : rest mass of electron or positron = 0.000549 u, .
A neutron is absorbed by a nucleus with subsequent emission of an -particle. Write the corresponding nuclear reaction and calculate the energy released in the reaction.