How Many Atoms per Cubic Centimeter Are in Radioactive Water After Cleanup?

  • Thread starter Thread starter NucE
  • Start date Start date
  • Tags Tags
    Radiation
AI Thread Summary
The discussion focuses on calculating the number of atoms per cubic centimeter in radioactive water after the cleanup at Three Mile Island, where 400,000 gallons of contaminated water remained. The primary radioactive source identified is Cesium-137, with an activity of 156E-6 Ci/cubic cm. To find the number of atoms, one must convert the activity in curies to decays per second, using the conversion factor of 3.7E10 decays/second per curie. The calculation involves determining the decay rate and the half-life of Cs-137 to establish the relationship between the decay rate and the number of atoms present. Understanding these principles is essential for accurate calculations in radioactive decay scenarios.
NucE
Messages
3
Reaction score
0

Homework Statement


"After cleanup at 3 mile island approximately 400,000 gal of radioactive water remained in the basement of the contaminated building. The principle sources of radioactivity were 137 Cs at 156E-6 Ci/cubic cm. How many atoms per cubic cm were in the water ?

Homework Equations


Not sure...

The Attempt at a Solution



6.022E23 * 156E-6/137 = 6.86E17
 
Last edited:
Physics news on Phys.org
It's a little more complicated than that.

A Curie (Ci) is 3.7E10 decays/second - so there are 156E-6 * 3.7E10 decays/sec/cc.

Then you need the activity or half-life of Cs137 to know what chance there is of a decay in a second for one atom, or alternatively how many atoms there needs to be to give the above overall decay rate.
 

Similar threads

Calculation: radioactivity [atoms/ccm]
Replies
1
Views
2K
Weight of water from molecular mass to grams per cubic centimeter
Replies
2
Views
4K
MHB Dylan's questions at Yahoo Answers regarding related rates
Replies
4
Views
5K

Hot Threads

Recent Insights

Back
Top