Question

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?

Answer #1

A radioactive sample contains 2.94 μg of pure11C, which has a
half-life of 20.4 min.
a) How many moles of 11C is present ini- tially? The value of
Avogadro’s number is
6.02 × 1023 nuclei/mol. Answer in units of mol.
b) Find the number of nuclei present initially. Answer in units
of nuclei.
c)Find the initial activity of the sample. Answer in units of
Bq.
d)Find the activity of the sample after 6.97 h. Answer 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.

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.

A radioactive nuclide has a half-life of 30.7 y. What fraction
of an initially pure sample of this nuclide will remain undecayed
at the end of 86.8 y?

The activity of a sample containing radioactive Ag-108 is
6.4×10^4 Bq. Exactly 12 min later, the activity is 2.0×10^3 Bq.
Calculate the half-life of Ag-108. Calculate the initial number of
Ag-108 nuclei in the sample.

The radioactive isotope 198Au has a half-life of 64.8 hr. A
sample containing this isotope has an initial activity (t = 0) of
1.5x 10^12 Bq. Calculate the number of nuclei that decay in the
time interval between t1 = 10 hr and t2 = 12 hr.
Please show and explain work, and do not use calculus to solve
it.

The radioactive nuclide 178 Ta undergoes first-order
decay with a half-life of 9.31 min. If a quantity of 178
Ta is produced, what fracrtion reamins after 82.5 seconds?
Please show me all steps in solving for the rate constant(k).
That's really all I need.

A sample of radioactive nuclei initially contains 6.00
×1010×1010 radon atoms. The half-life of this type of nucleus is
500 days. How many nuclei have decayed after 167 days?
A sample of radioactive nuclei initially contains
6.00 radon atoms. The half-life of this type of nucleus
is 500 days. How many nuclei have decayed after 167 days?
2.00×1010
4.00×1010
1.24×1010
4.76×1010

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

The
radioactive isotope Gold-198 has a half-life of 64.80 hrs. A sample
containing this isotope has an initial activity of 40.0 μCi.
Calculate the number of nuclei that will decay in the time interval
from 10 hrs to 12 hrs.[10 marks]

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 8 minutes ago

asked 34 minutes ago

asked 37 minutes ago

asked 53 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago