Finding the quantity of a radioactive substance and standard units

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SUMMARY

The discussion centers on the calculation of the quantity of a radioactive substance remaining after a specified half-life using the formula T1/2 = 0.693/lambda. It is established that while time (t) and half-life (T1/2) do not need to be converted to standard units, they must be expressed in the same units for accurate calculations. Lambda (λ) inherently includes units of reciprocal time, ensuring that calculations yield correct results as long as the units are consistent.

PREREQUISITES
  • Understanding of radioactive decay and half-life concepts
  • Familiarity with the formula T1/2 = 0.693/lambda
  • Knowledge of units of time (seconds, minutes, years)
  • Basic algebra skills for manipulating equations
NEXT STEPS
  • Study the derivation of the half-life formula T1/2 = 0.693/lambda
  • Learn about the implications of lambda (λ) in radioactive decay
  • Explore unit conversions in scientific calculations
  • Investigate applications of radioactive decay in various fields such as medicine and archaeology
USEFUL FOR

Students and professionals in physics, chemistry, and engineering, particularly those involved in nuclear science and radioactive material management.

EIRE2003
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When finding the quantity of a radioactive substance remaining after a half life of time t, using the formula, T1/2=.693/lambda. do u have to convert the time to standard units, the second, if it is in mins, or yrs or days or months watever?
 
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EIRE2003 said:
When finding the quantity of a radioactive substance remaining after a half life of time t, using the formula, T1/2=.693/lambda. do u have to convert the time to standard units, the second, if it is in mins, or yrs or days or months watever?

No, but t and T1/2 has to be in same units.
 
EIRE2003 said:
When finding the quantity of a radioactive substance remaining after a half life of time t, using the formula, T1/2=.693/lambda. do u have to convert the time to standard units, the second, if it is in mins, or yrs or days or months watever?

Lambda will have the appropriate units of reciprocal time included. If you know the half life and solve for lambda, the answer will have the correct units for lambda. If you are given lambda and calculate T1/2, it will have the correct units. If you are given lambda without units, you don't have enough information to find T1/2.
 

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