The half-life of a radioisotope is the amount of time it takes for<em><u> half the sample to decay. </u></em>
<em><u>Radioactive particles or nuclides undergoes the process called radioactivity </u></em>which is the spontaneous decay of radioactive materials to emit radiation such as beta particle, alpha particle and also associated with energy loss.
<em><u>Half-life is the time taken by a radioactive substance or material to decay by half of the original isotope to decay.</u></em> For instance; <em><u>when the half life of 100 g of substance X is 5 years, this means that after five years only 50 g of the substance would remain.</u></em>
The half-life of a radioisotope is the amount of time it takes for half the sample to decay. The correct option among all the options that are given in the question is the second option. The other choices are incorrect and can be negated. I hope that this is the answer that has come to your great help.
a stationary front moves when a cold front or warm front stops moving this happens when two masses of air are pushing against each other but neither is powerful enough to move the other winds blowing parallel to the front instead of perpendicular can help it stay in place.