If a 300g sample of a substance has a half-life of 5 days, how much of the substance will decay after 22 days?

A)293.4 g
B)290.6 g
C)285.8 g
D)299.9 g

First you need to know k in the formula

ln(No/N) = kt.
No = 300 g
N = what you solve for. This is what's left
k = 0.693/half life
t = time = 22 days
Then you want 300-N to give you what has decayed.
Post your work if you get stuck.

Im not sure how to solve the question

When I plugged in those numbers it ends up with 300/N=(0.693)(22) which gets me about 19.677. Then 300-19.677 gets me 280.323 and thats not an available answer.

My instructions were to post your work, not your answers with no work.

To determine how much of the substance will decay after 22 days, we can use the formula for exponential decay:

N(t) = N0 * (1/2)^(t / T)

Where:
N(t) is the remaining amount of the substance after time t
N0 is the initial amount of the substance
t is the time that has passed
T is the half-life of the substance

In this case, N0 (the initial amount) is 300g, the half-life (T) is 5 days, and t (the time that has passed) is 22 days.

Plugging these values into the formula:

N(22) = 300 * (1/2)^(22 / 5)

Calculating this expression, the value of N(22) is approximately 290.6 g.

Therefore, the correct answer is B) 290.6 g.

What is your answer?