Questions

1. A sample is known to contain some of the radioisotope Cobalt 60 which has a half life of 5.3 years. The sample has an activity of 340 Bq.

a) Calculate the decay constant of Co⁶⁰

b) Calculate the number of atoms of Co⁶⁰ present in the sample

c) Calculate the mass of Co⁶⁰ in the sample  ( 1 mole of the isotope, 6.02 x 10²³ atoms,  has a mass of 60g )

d) What would the activity of the sample be after 5.3 years?  After 10.6 years?

e) ( HARDER) What would the activity be after 2 years?

2. Calculate the mass number and atomic number of the daughter nucleus resulting from the decay of the following. (You will need a periodic table)

a) ²⁰⁸Po₈₄ decays by emitting an alpha

b) ²¹¹Fr₈₇ decays by emitting an alpha

c) ⁶He₂ decays by emitting a beta particle

d) ²⁴Na₁₁ decays by emitting a beta particle