Question

A 200. 0-ng sample of sodium-24 was stored in a lead-lined cabinet for 45 hours. The half-life of sodium-24 is 15 hours. How much sodium-24 remains?

Answer 1

Answer:

25 gm would be left

Explanation:

45 hours is 3 half lives

200 gm  * 1/2 * 1/2 * 1/2 = 25 gm