Answer:
a) 29.0 years
b) 0.89 g
Explanation:
Using the formula
t1/2= t×ln2/ln(No/Nt)
Where
Nt= mass of radioactive isotope at time= t =0.953g
No= initial mass of radioactive isotope present= 1.000g
t= time taken for N mass of radioactive isotope to remain = 2 years
t1/2 = half-life of radioactive isotope= ???
Substituting the values
t1/2= 2 × ln2/ln(1.000/0.953)
t1/2= 2× 0.693/0.048
t1/2= 29 hours
b)
N= No(1/2)^t/t1/2
Where t= 5 years
N= 1.000(1/2)^5/29
N= 1.000(1/2)^0.17
N= 0.89g
