1.
2 gram of
charcoal from tree gives a radioactive carbon count of 18 disintegrations per
minutes. Charcoal from museum of 14gm
of mass gives a count of 12 min-1 .if the T1/2 of 14C is 5739 what is the age of the archeological
specimen. Deduce the equation which produces the radioactive carbon mentioning
the source of the nuclides.
2.
The ration of radiocarbon in a piece of wood 13%
that of the atmosphere, calculate the age of the wood. if the disintegration
constant H is 1.24 X 10-4/year.
3.
5gm of radioactive element decays by beta
emission to 0.250g in 400hrs , calculate
the decay constant.
4.
131I has a half life period of 8 days
. what is its decay constant.
5.
If the decay constant of a radioactive element
of mass 20gm is 1.234X104/hrs, calculate how long the element will
stay if its half life is 30 minutes.
6.
0.8g of Co decay by beta emission to 0.125g in
720,000 secs, what is its half life period
7.
What is the mean life time of a radioactive
element whose half life is 60 years.
8.
The half life of 236Ra is 1620 years,
calculate the half life in per sec.
9.
By natural radioactivity,238U, emits
an alpha particles. the residue heavy nucleus from this radioactive process is
UXI, the UX1 in turn emits beta-particles. the heavy residual nucleus from this
radioactive process is called UX2, determine the atomic number of (i)UX1 (ii)UX2.
10.
At a
certain instant , a radioactive materials contains 1012 atoms . the
half life of the material is 30 days.
·
calculate the number of disintegrations in the
first second.
·
how long will elapse before 104 atoms
remain?
·
what is the count rate at this time.
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