Thorium-234 has a half-life of 24.1 days.

How much of a 100-g sample of thorium-234 will be unchanged after 48.2 days?

75 g

50 g

25 g

12.5 g

1 answer

25 g

After 24.1 days, half of the 100-g sample will remain unchanged, leaving 50 g.

After another 24.1 days (total of 48.2 days), half of the remaining sample will remain unchanged, leaving 25 g.