Technetium has a half-life of six hours. If you obtain 100g of a pure technetium sample, after 18 hours how much of the pure substance will be remaining?

Question

asked Apr 23, 2021 156k views

1 Answer

Jeanluca Scaljeri · Answer 1 · 2021-04-27T02:22:08+0000

Answer: 12.5 grams.

Step-by-step explanation:

You can find the amount of pure substance remaining by using the half-life formula:

$Q_(1)=Q((1)/(2))^{(t)/(t2) }$

Where t is the amount of time, and t2 is the half life of the substance.

Substituting our values for the variables, we get this equation:

$Q_(1) = 100((1)/(2))^3\\\\Q_(1) = 100((1)/(8))\\\\Q_(1) = 12.5$

After 18 hours, there will be 12.5 grams of the substance remaining.