Anyone know how to find the length of x using the 30,60,90 method?
2 answers:
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Answer :
The amount after 1000 years will be, 5.19 grams.
The amount after 10000 years will be, 0.105 grams.
Step-by-step explanation :
Half-life = 1599 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the amount after 1000 years.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = 1000 years
a = initial amount of the reactant = 8 g
a - x = amount left after decay process = ?
Now put all the given values in above equation, we get
Thus, the amount after 1000 years will be, 5.19 grams.
Now we have to calculate the amount after 10000 years.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = 10000 years
a = initial amount of the reactant = 8 g
a - x = amount left after decay process = ?
Now put all the given values in above equation, we get
Thus, the amount after 10000 years will be, 0.105 grams.
Answer:
95.15%
Step-by-step explanation:
We have that the mean (m) is equal to 20, the standard deviation (sd) 3
They ask us for P (x <25)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / sd
We have all these values, replacing we have:
z = (25 - 20) / (3)
z = 1.66
With the normal distribution table (attached), we have that at that value, the probability is:
P (z <1.66) = 0.9515
Which means that the probability that it arrives before 25 minutes is 95.15%
