[spirochete]

Mods can move this to nuclear chemistry if it should be there, but I didn't want to muck up that forum with my trivial questions.  This is my first day teaching myself nuclear chemistry.  We didn't cover this at all in my gen chem class.  Here are a  question where my answers seem to be conflicting with the book I'm using:

1) Suppose a parent isotope emits a positron, which then alpha decays.  If the final atom is Iron (atomic mass 60 and atomic number 26), what is the original atom's atomic #/atomic mass?

My answer is 64 and 29.  Working backwards, the intermediate is 64/28, coming from loss of 4 AMU, and 2 protons.  The precursor to that has an atomic mass number of 29 because it lost the equivalent of a proton during the positron emission.

The book's answer is 64/28.  There is a brief explanation that I don't understand saying you should reference the periodic table and see that A# of 29 means the unknown is copper, and since the weight=64, somehow the answer has an atomic mass number of 28.  What the heck are they talking about?

[enahs]

Positron = antielectron.

[Borek]

Positron = antielectron.

And that's exactly where the problem starts. Charge - you lose e⁺ and alpha²⁺ = +3 together. Mass - you lose alpha - so 4 amu. You end with 60/26 so starting point should be 60+4/26+3. No idea why 28, but then in my case it is "nucular", not nuclear

Mitch?

[enahs]

Your typing of the books explanation confused the hell out of me.

I would check the publishers website for an errata, and see if it has one and if it lists that as a mistake.