Answer:
Explanation:
1) During the diagnosis of thyroid disease a 10 g sample of I-131 is used. After a period of 32 days, how much sample is still radio active.?
Answer:
0.625 g
Explanation:
HL = Elapsed time/half life
32 days/8 days = 4
At time zero = 10 g
At 1st half life = 10/2 = 5 g
At 2nd half life = 5/2 = 2.5 g
At 3rd half life = 2.5 /2 = 1.25 g
At 4th half life = 1.25 / 2 = 0.625 g
After 32 days still 0.625 g of I-131 remain radioactive.
2) what was the original mass of sample Tc-99 that was used to locate the brain tumor If 0.10 g of a sample remains after 30 days? (half life 6 days)
Answer:
0.32 g.
Explanation:
Half life = time elapsed / HL
Half life = 30 days / 6 days = 5
At 5th half life = 0.10 g
At 4th half life = 0.2 g
At 3rd half life = 0.4 g
At 2nd half life = 0.8 g
At 1st half life = 0.16 g
At time zero = 0.32 g
The original amount was 0.32 g.
3) write the beta decay equation of I-131?
Equation:
¹³¹I₅₃ → ¹³¹Xe₅₄ + ⁰₋₁e
Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminium is used to block the beta radiation
¹³¹I₅₃ → ¹³¹Xe₅₄ + ⁰₋₁e
The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.
