The amount of time it takes for one-half of the original amount of an isotope to decay is known as its question 9 options: correlation half-life period radioactivity

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.