Carbon is allowed to diffuse through a steel plate 12 mm thick. the concentrations of carbon at the two faces are 0.86 and 0.40 kg c/m3 in fe, which are maintained constant. if the preexponential and activation energy are 6.2 × 10-7 m2/s and 80,000 j/mol, respectively, compute the temperature (in k) at which the diffusion flux is 6.3 × 10-10 kg/m2-s.

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

explanation:

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