wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Assume that the isotope U238 and U235 are found in the ratio 64 : 1 presently at a planet. At the time of the creation of the planet, they were present in an equal ratio.What is the age of the planet (in million years 106 ). The half-life period of U238 and U235 are 4.45×109 and 7.0×108 year respectively.

Open in App
Solution

Let the age of the planet be = t years
Given,
U238o:U235o=1:1
U238t:U235t=64:1
Now, λ238.t=lnU2380U238t and λ235.t=lnU2350U235t

Hence,(λ238λ235)t=ln(U2380U238t×U235tU2350)
ln 2×(14.45×10917×108)=ln(164)

ln 2×(4.450.74.45×0.7×109)t=ln(641)ln 2×(3.754.45×0.7×109)t=6 ln 2

t=4.45×0.7×109×63.75=4984×106 years.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Application of Radioactivity
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon