Question

The half-life of silicon-32 is 100 years. How much of a 120g sample will remain after 300 years?

a) 15g
b) 30g
c) 45g
d) 60g

Answer 1

To calculate how much of the sample remains after a certain amount of time, we can use the formula: Remaining mass = Initial mass * (1/2)^(number of half-lives). After 300 years, the remaining mass of a 120g sample of silicon-32 is 15g.

Step-by-step explanation:

To calculate how much of the sample remains after a certain amount of time, we can use the formula:

Remaining mass = Initial mass * (1/2)^(number of half-lives)

In this case, the half-life of silicon-32 is 100 years. After 300 years, there have been 3 half-lives (300/100).

So, the remaining mass = 120g * (1/2)^3 = 120g * (1/8) = 15g.

Therefore, the answer is (a) 15g.