Radioactive reactions -half-life Decay physics 30

[cathoderay]

1. hi i would like to now how i could do this?
the question says:
iodine-131 is a radiactive element used in the medical diagnosis and treatment of thyroid problems. iodine-131 undergoes simultaneous beta and gamma decay and has a half-life of 8.00 days.

2.im ask to write the complete decay equation for iodine-131



3. i know the formula for the life time is N=No(1/2)^n and n=time after/half-life...T(1/2)
but I am not sure if that's the equation to do the decay...
...or the complete decay equation they are asking for is a series of radioactive elements.. like the folowing
ex: 226 Ra--->222 Rn + 4 He
... 88....86...2

if is as the example I am not sure how to do it..could someone explain me how could i do it ? thanks

 

[Shooting Star]

...or the complete decay equation they are asking for is a series of radioactive elements.. like the folowing
ex: 226 Ra--->222 Rn + 4 He
... 88....86...2

if is as the example I am not sure how to do it..could someone explain me how could i do it ? thanks

Yes, this is what they are asking.

If an electron is emitted by the nucleus, what happens to the atomic number?

 

[daveb]

Since they mention it's a beta emitter, but also mention the half life, I can see the confusion. Typically, in health physics and nuclear engineering, when asked for the decay equation for a radioactive element, it's asking for A(t) = A(0)exp(-lambda*t). However, it (i.e., the decay equation) is sometimes used in the second manner, as pointed out by Shooting star. I suppose it depends on the chapter of the book you're using. From the title of your post, it says half life decay, so I would go with the first

 

[Shooting Star]

After reading the original post once more, I agree with user daveb. Sorry for misleading the OP a bit.