Base your answers to questions 62 through 65 on the information below
and on your knowledge of chemistry.
Some isotopes of potassium are K-37, K-39, K-40, K-41 and K-42.
The Natural abundance and the atomic mass for the naturally occurring
isotopes of potassium are shown in the table below.
62 Identify the decay mode of K-37 [1]
63 Complete the nuclear equation in your answer booklet for the decay of
K-40 by writing a notation for the missing nuclide. [1]
64 Determine the fraction of an original sample of K-42 that remains
unchanged after 24.72 hours. [1]
Answer--> 1/4
Use table N
Work not required 24.72h/12.36h= 2 half
lives
1--> 1/2--> 1/4 |
65Show the correct numerical setup for calculating the atomic mass of
potassium. [1]
Answer-->
((93.26)(38.96))+((0.01)(39.96))+((6.73)(40.96)) |
100 |
or
((93.26)(0.3896))+((0.0001)(39.96))+((6.73)(0.4096)) |
on to
Questions 66-68 |