Your answer is 36. hope it helps!
The mass of substance left after 7 days is 13.09 g
The mass of substance left, N is given by
N = N₀exp(-λt) where λ = decay constant and N₀ = initial mass of substance present = 24 g and t = time
Also, λ = 0.693/t' where t' = half-life of iodine = 8 days
So, λ = 0.693/t'
λ = 0.693/8
λ = 0.086625/day
Since the mass of substance left is N = N₀exp(-λt) and we require the mass of substance after t = 7 days,
N = N₀exp(-λt)
N = 24 gexp(-0.086625/day × 7 days)
N = 24 gexp(-0.606375)
N = 24 g × 0.5453
N = 13.09 g
So, the mass of substance left after 7 days is 13.09 g
Learn more about radioactive decay here:
brainly.com/question/23705307
1. 24%
2. 13%
3. 60%
1. Since 6/25 is .24, 24% of the class was absent
2. He spent 3 hours in total.. Divide is by 24 because there are 24 hours in a day. 3/24 is 0.125 for 13% of the day
3. He ran 3 of the 5 miles, so 3/5 = 0.6.. meaning 60%. The time doesn’t matter
<em>The answer you are looking for is: </em>
<em><u>x=5 </u></em>
<em>Hope that helps!! </em>
<em>have a wonderful day!!</em>
