Seventh Element
Chemistry Help…(with half life problem)?
Potassium is a necessary nutrient for all living things and is the seventh most abundant element on the surface of Earth,making up about 1.5% of Earth’s crust. About 0.01% of natural potassium atoms are the radioisotope potassium-40. K-40 has a half-life of nearly 1.3 billion years.
a. How much of the K-40 present at Earth’s formation remained after one half-life?
b. Assuming the Earth is about 4.5 billion years old, roughly how many times more potassium-40 was present when Earth formed than is present now?
Thanks and 10 pts to the most helpful answer!
a. after 1 half-life, half of the original k-40 remained…a half-life is the amount of time it takes the original amount to decay until there’s only half left.
b. between 8 and 12 times the amount present now. nearly three and a half half-lives have gone by. after the first half-life, the amount was half the original, after the second, there amount left was 1/4th the original, after the third the amount left was 1/8th the original, and since another half of a half-life has gone by, the amount is now down to about 1/12th of the original amount
7th Element – Ride Chariot
