A 300-g sample of ²¹⁸Po undergoes $\alpha$ decay with a half-life of 3.1 minutes. After 15.5 minutes, A) 9.38 g of ²¹⁴Pb would be formed. B) 18.8 g of ²¹⁴Pb would be formed. C) 120 g of ²¹⁴Pb would be formed. D) 281 g of ²¹⁴Pb would be formed. E) 291 g of ²¹⁴Pb would be formed.

Question

Quizplus · Accepted Answer

After 15.5 minutes, which is 5 half-lives (15.5 / 3.1), the remaining amount of ²¹⁸Po is 300 g / 2^5 = 9.375 g. Therefore, the amount of ²¹⁴Pb formed is 300 g - 9.375 g = 290.625 g, which rounds to 291 g.

A 300-G Sample of 218Po Undergoes α\alphaα Decay with a Half-Life of 3

A 300-G Sample of ²¹⁸Po Undergoes $\alpha$ Decay with a Half-Life of 3