Question

Research shows that the radioactive isotope Plutonium-238 has a half-life of 87.7 years

Use the following to construct a function that will model the amount of Plutonium-238 remaining after t years, from an initial amount of 15 kg.

Q(t)=Pert

Where Q(t) describes the amount of Plutonium-238 remaining after t years from an initial quantity of P kg.

- Q(t)=
- How long (in years) will it take for the amount of Plutonium-238 remaining to reach 3 kg?

Answer #1

Plutonium-238 is a radioactive isotope of plutonium that was
often used as the power supply in cardiac pacemakers. One gram of
Pu-238 generates approximately 0.5 watts of power. Suppose that 2
grams of the isotope were inserted into the pacemaker battery as a
sealed source in the patient to provide power to the pacemaker. The
rate at which Pu-238 decays can be modeled as
r(x) = −0.0158(0.992127535x) grams per year
where t is the number of years since the 2...

The radioactive plutonium isotope, 239Pu, has an half-life of 24
100 years and undergoes alpha decay. The molar mass of 239Pu is
239.0521634 amu. The sample initially contains 10.0 g of 239Pu.
(a) Calculate the number of moles of 239Pu that are left in the
sample after 15 000 years. (4)
(b) Determine the activity of 239Pu after 15 000 years, in units
of Bq.

The radioactive plutonium isotope, 239Pu, has an
half-life of 24 100 years and undergoes alpha decay. The molar mass
of 239Pu is 239.0521634 amu. The sample initially
contains 10.0 g of 239Pu. (a) Calculate the number of
moles of 239Pu that are left in the sample after 15 000
years. (4) (b) Determine the activity of 239Pu after 15
000 years, in units of Bq.

Complete the table for the radioactive isotope. (Round your
answers to two decimal places.)
Isotope
Half-life
(in years)
Initial
quantity
Amount after
1000 years
Amount after
10,000 years
239Pu
24,100
?grams
grams
?0.4 grams

The radioactive isotope thorium 234 has a half-life of
approximately 578 hours.
If a sample has an initial mass of 64 mg, a function that models
the mass in mg after t hours is a(t) =
The initial mass will decay to 12 mg after ______ hours
Radioactive decay equation:
a(t) = a0⋅2 ^ (−t / h)
a0 = starting amount
a(t) = amount after t hours
h = half life in hours

The half-life for the radioactive decay of U−238 is 4.5 billion
years and is independent of initial concentration.
A) How long will it take for 10% of the U−238 atoms in a sample
of U−238 to decay?
Express your answer using two significant figures.
B) If a sample of U−238 initially contained 1.4×1018
atoms when the universe was formed 13.8 billion years ago, how many
U−238 atoms will it contain today?
Express your answer using two significant figures.

Strontium-90 (90Sr) is a radioactive isotope with a half-life of
28.8 years. What percentage of this isotope remains after 11.4
years?

The
radioactive nuclide Plutonium-199 has a half-life of 43.0 min. A
sample is prepared that has an initial activity of 7.56 ×1011 Bq.
i. How many Plutonium-199 nuclei are initially present in the
sample?
ii. How many are present after 30.8 min?
iii. What is the activity at this time?

15.57 The half-life for the radioactive decay of U−238 is 4.5
billion years and is independent of initial concentration. How long
will it take for 20% of the U−238 atoms in a sample of U−238 to
decay? Express your answer using two significant figures. If a
sample of U−238 initially contained 1.1×1018 atoms when the
universe was formed 13.8 billion years ago, how many U−238 atoms
will it contain today? Express your answer using two significant
figures.

The radioactive isotope 234Pa has a half-life of 6.70
h. A sample containing this isotope has an initial activity
(t = 0) of 35.0µCi. Calculate the number of nuclei that
decay in the time interval between t1 = 7.0 h
and t2 = 14.0 h.
___________ Nuclei

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 5 minutes ago

asked 51 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago