Answer:
Step-by-step explanation:
Isotope is an element that has the same number of protons and electrons but has a DIFFERENT number of neutrons. Radioactive isotopes are used in the medical field. many times they call them tracers. They can be used for thyroid analysis, heart analysis, kidney and bladder functions.
water is the universal polar molecule. due to the unequal sharing of electrons it makes the oxygen end slightly negative and the hydrogen ends slightly positive. This allows for attraction between opositely charged particules. Thus is can transport electrolytes in our bodies etc.