Please answer these questions for me. 10 A. How many years would pass if only 25% of the Potassium-40 radioactive elements are left?

10B. How many half-lives has the sample gone through if only 25% of the Potassium-40 radioactive elements are left?

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed