Question

Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion 5 billion years ago. The other was created in a nuclear reactor 5 minutes ago. The probability of decay during the next time is
A. Different for each nuclei
B. Nuclei created in explosion decays first
C. Nuclei created in the reactor decays first
D. Independent of the time of creation

Answer 1

Hint: A process by which unstable nuclei lose energy in form of radiation is called Radioactive decay and this process is spontaneous.

Complete step by step solution:
Two nuclei of the same nuclide are created; one is created in a supernova explosion 5 billion years ago and the other in a nuclear reactor 5 minutes ago. We have to find their probability of decay next time.

Radioactive decay is a spontaneous process which does not depend on external factors such as temperature and pressure, it is possible only for unstable nuclei i.e. nuclei having unequal numbers of neutrons and protons.

The rate of disintegration for a radioactive sample is directly proportional to the number of atoms in the sample at a particular instant of time. It is impossible to predict the decay of a particular atom of a radioactive sample during a given time and it is independent of the time of creation.

Therefore, option D is the correct option.

Note: According to the Radioactive decay formula derived from the law of disintegration number of atoms present in the radioactive sample is directly proportional to the initial number of atoms in the sample and t in the formula \[N = {N_0}{e^{ - \lambda t}}\] represents the time at which rate of decay is to be calculated not the time of creation.