Joules in this absorption/thyroid question

Smythe

In the attachment the question is given in bold, and the correct solution under this.

I'm wondering how has the figure of 0.96 J, in the solution, been calculated?

It is also known that Q = 0.606 MeV (though I'm not sure if relevant to this part of the question)

Delphi91

Smythe wrote: »

In the attachment the question is given in bold, and the correct solution under this.

I'm wondering how has the figure of 0.96 J, in the solution, been calculated?

It is also known that Q = 0.606 MeV (though I'm not sure if relevant to this part of the question)

(1) What is the equivalent of 1eV in Joules?

(2) Each emitted electron has an energy of 0.2MeV. So what is that in Joules?

According to the question, each absorbed Iodine nucleus decays by emission of an electron. The answer states the number of nuclei absorbed, and therefore the number of electrons also.

From (2) above, you know what the equivalent energy of the electrons is, so what is the total amount of energy?

Smythe

Thanks very much Delphi91, I was able to calculate the 0.96 J. Thanks for that!

Delphi91 wrote: »

According to the question, each absorbed Iodine nucleus decays by emission of an electron.

Do you know this from the fact that B- decay is stated in the question?

Delphi91

Smythe wrote: »

Thanks very much Delphi91, I was able to calculate the 0.96 J. Thanks for that!

Do you know this from the fact that B- decay is stated in the question?

Yes. A beta particle is a high energy electrons or positrons. If the decay involves beta- emission, then it's an electron. If it involves beta+ emission, then its a positron.

Smythe

Cheers.