Question

A potassium isotope has a half-life of 1.25 billion years. Given that scientists estimate Earth's age to be 4.6 billion years, what is the most likely percentage of parent to daughter isotopes of this element currently existing on Earth?

Less than 10 percent

25 percent

50 percent

More than 75 percent

Answer 1

this is ur hw?

Answer 2

my sister hw but i am try to help her but i dont nou that question

Answer 3

or ok give me a minute

Answer 4

ok thanks :)

Answer 5

ok so first u must find how many half lives past so that's 4.6/1.25 then u must use the eqn to find out wat fraction to multiply the original value by (1/2)^[no of halflives] and multiply that ans by 100 to find the percentage

Answer 6

so the answer is 50 percent?

Answer 7

no

Answer 8

therefore the ans is less than 10%