Answer:
See Explanation
Explanation:
Given that;
N/No = (1/2)^t/t1/2
Where;
No = amount of radioactive isotope originally present
N = A mount of radioactive isotope present at time t
t = time taken
t1/2 = half life
N/1000=(1/2)^3/6
N/1000=(1/2)^0.5
N = (1/2)^0.5 * 1000
N= 707 unstable nuclei
Since the value of the initial activity of the radioactive material was not given, the activity of the radioactive material after three months is given by;
Decay constant = 0.693/t1/2 = 0.693/6 months = 0.1155 month^-1
Hence;
A=Aoe^-kt
Where;
A = Activity after a time t
Ao = initial activity
k = decay constant
t = time taken
A = Aoe^-3 *0.1155
A=Aoe^-0.3465
One: looks to be correct for both answers. Certainly the first one is. The second depends on your other choices. But military use is one.
Two: is correct. Pd has (in this case) an atomic mass of 114 and its number is 46
Three: Even with my slop numbers, 4.98 is the answer (although I get 4.99 but again, my numbers are pretty sloppy).
Four: Slop numbers say 78.3, but 78 is the right answer.
Five: Slop numbers agree with Al2S3. I think that's D
They are all correct. Very Fine Work.
