THIS SERIES OF REACTIONS IS A TRANSMUTATION SERIES, A SERIES OF NUCLEII DECOMPOSE INTO ITHER SPECIES UNTILL A STABLE ISOTOPE IS PRODUCED TO END THE PROCESS. A VARIETY OF RADIATION IS EMITTED.

1
THIS SERIES OF REACTIONS IS A TRANSMUTATION
SERIES, A SERIES OF NUCLEII DECOMPOSE INTO ITHER
SPECIES UNTILL A STABLE ISOTOPE IS PRODUCED TO
END THE PROCESS. A VARIETY OF RADIATION IS
EMITTED.
2
QUESTIONS
8- WHAT IS THE TIME (h) FOR POTASSIUM-42 TO
UNDERGO THREE HALF-LIFE PERIODS?
1
1/2
1/4
3RD T
2ND T
1ST T
1/8
NUMBER OF HALF LIFE PERIODS t/T WHERE T
HALF LIFE (TABLE N) t TIME
ELAPSED
3 t/ 12.4 h 37.2h
3
9 If a sample of 10 grams decays to 5 grams
after 2 days what is the half life?
1
1/2
1/4
3RD T
2ND T
1ST T
1/8
FRACTION REMAINING REMAINING/ORIGINAL
5/10 ½ REMAINING
It takes one half life to get to ½ the original.
In this question that is 2 days
4
10- After 6 days what fraction of an element
with a half life 2 days remains.
NUMBER OF HALF LIFE PERIODS t/T WHERE T
HALF LIFE (TABLE N) t TIME
ELAPSED
T t/T 6/2 3
1
1/2
1/4
3RD T
2ND T
1ST T
1/8
6 days is 3 half lives and 1/8 of the sample
remains,
5
11- How many grams of I-131 will persist after
24 d if 40.0g was present initially.?
Fraction persist (1/2)t/T (1/2)24d/8.07d
1/8 1/8
of 40 5g
40g
20g
10g
3RD T
2ND T
1ST T
5g