I need to know how much of a 2g sample of Technetium-99 would be left after 12 hours.
The half life of Technetium-99 is 6 hours
So half of it will be gone in 6 hours.
Another half of it will be gone in 12 hours. You started with 2g.
At the end of 6 hrs there will be 1 g.
At the end of 12 hours there will be 1/2 g left? right?
To find out how much of a 2g sample of Technetium-99 would be left after 12 hours, we can use the concept of half-life.
The half-life of Technetium-99 is given as 6 hours. This means that after every 6 hours, half of the sample will decay.
To calculate the amount left after 12 hours, we need to determine the number of half-lives that have occurred in that time. Since the half-life is 6 hours, there will be 2 half-lives in 12 hours (12 ÷ 6 = 2).
To calculate how much is left after each half-life, we can use the following formula:
Amount left = Initial amount × (1/2)^(number of half-lives)
In this case, the initial amount is 2g, and there are 2 half-lives. Plugging these values into the formula, we get:
Amount left = 2g × (1/2)^(2)
Calculating this expression:
Amount left = 2g × (1/4)
Simplifying:
Amount left = 2g/4
Amount left = 0.5g
Therefore, after 12 hours, there would be 0.5g of Technetium-99 left from the initial 2g sample.