Question

The half-life of I-37 is 8.07 days. If 25 grams are left after 40.35 days, how many grams were in the original sample?

Answer 1

Answer:

800 g

Explanation:

We can express the decay of I-37 using the formula:

• Final Mass = Initial Mass * $0.5^{\frac{Time}{Half-Life} }$

We input the data:

• 25 g = Initial Mass * $0.5^{(\frac{40.35}{8.07})}$

And solve for Initial Mass:

• 25 g = Initial Mass * $0.5^{5}$

• 25 g = Initial Mass * 0.03125

• Initial Mass = 800 g

Meaning that out 800 grams of I-37, only 25 will remain after 40.35 days.