If the number of radioactive nuclei present is cut in half ,how does the activity change
The activity will also be cut in half. Activity is proportional to the number of radioactive nuclei present, so if the number of nuclei is halved, the activity will also be halved.
When the number of radioactive nuclei present is halved, the activity also reduces by half.
The activity of a radioactive substance is directly proportional to the number of radioactive nuclei present. Activity is defined as the number of radioactive decays that occur per unit time. Therefore, if the number of radioactive nuclei is reduced to half, there will be half as many decays happening per unit time, resulting in a decrease of activity by half.