Select the correct answer from the drop-down menu. A scientist digs up sample of arctic ice that is 458,000 years old. He takes it to his lab and finds that it contains 1.675 grams of krypton-81.

If the half-life of krypton-81 is 229,000 years, how much krypton-81 was present when the ice first formed?

Use the formula N = N0 .

The ice originally contained *Drop down menu* (0.419) (2.34) (2.81) (3.35) (6.70)
grams of krypton 81.