A Test Tube of an Isotope Having a Decay Constant $10 ^{- 6}$

question 49

Short Answer

A test tube of an isotope having a decay constant of 0.765 × $10 ^{- 6}$ $\mathrm { s } ^ { - 1 }$ contains 3.0 × $10^{17}$ nuclei of this isotope.
(a)What is the half-life of this isotope?
(b)What is the initial activity (in Bq)of the isotope?
(c)What is the activity of the isotope after 12 days?