What is the definition of the half-life of a radioactive isotope? The time it takes for half the parent nuclei in a sample to become daughter nuclei.

The half-life is the amount of time it takes for a given isotope to lose half of its radioactivity. If a radioisotope has a half-life of 14 days, half of its atoms will have decayed within 14 days. In 14 more days, half of that remaining half will decay, and so on.

iron would move it is magnetic there is a mag field around the current in the wire

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this