Question

If a rock sample has a half life of 10 years, and has 100 atoms of parent material today, how many half lives will have passed before it has only 25 atoms of parent material left?

Answer 1

1 half life,2 half life's to equals 25 atoms left.

The 1 half life gets the amount of atoms to 50.

Two half life's gets the amount of atoms to 25.

Half life's takes the amount of substance and Half's it every certain amount of years.

Answer 2

1 half life, two half lifes to equal 25 atoms left

The 1 half life gets the amount of atoms to 50

2 half lifes gets the amount of atoms to 25.

Half life takes the amount of substance and halves it every certain amount of years.