After 30 minutes, 30 grams of a sample of Radon-222 remains unchanged. If the original sample had a mass of 960 grams, what is the half-life of the Radon-222? A.
8 minutes

B.
6 minutes

C.
3 minutes

D.
15 minutes

Which of the following warnings would an agricultural chemist tell a farmer who wants to recycle his or her own ammonia? recycling ammonia is a difficult process that sometimes takes weeks. recycling ammonia requires a degree in biochemistry or a related field. recycling ammonia can be harmful because it is highly flammable and toxic. recycling ammonia costs too much money considering the price of the necessary chemicals.