Consider the following two statements What is the likelihood

Consider the following two statements: What is the likelihood that in a particular time interval any nucleus in the ensemble will decay? Will a particular nucleus decay in this time interval? Are both of these statements valid questions to ask quantum mechanically? Explain your answer.

Solution

the two statements are not valid questions to ask. Actually decaying of a nucleus in a particular interval of time could not be predicted at all. It is a stastical process which simply obeys laws of chance. There is no cause-effect relationship involved in the decay of an particular nucleus.