## Mashy 3 years ago Urgent.. Radioactivity doubt, beta decay in a beta minus decay, the equation is zXa = (z+1)Ya + beta- z- atomic number, a - mass number.. now whats bothering me is the NUMBER OF ELECTRONS that our Y would have.. why does it have (z+1) electrons now??? it should have only z electrons cause in the disintegration, a neutron becomes proton and a beta minus particle.. hence increase in number of protons, but why does electron number of the Y become z+1 too??

1. Mashy

ishaan help me :D.. you have this in your syllabus right :D

2. Ishaan94

Umm that is the atomic number, atomic number is defined as number of protons not number of electrons.

3. Mashy

yes.. but in another chapter, when they consider neutrino hypothesis, while considering the mass of the daughter atom, they subtract Z+1 into mass of electron.. so that means they consider that the daugher atom has Z+1 electrons right!

4. Ishaan94

I don't know what you mean by neutrino hypothesis or maybe I can't recall it or maybe my head isn't working now. But from what I have read and what I can recall. In a minus Beta decay the neutron breaks into proton and electron and anti-neutrino.

5. Ishaan94

Hence, +1 proton or you can +1 (increase by 1) in the atomic number.

6. Mashy

so you are saying, that my daugther atom is +1 ion right? cause it has one extra proton in its nucleus? P.S. neutrino hypothesis, is when they calculate the kinetic energies and find out that something besides the beta particle must be present, and then they say there are something called as neutrinos

7. Ishaan94

$^{32}_{15}X \to ^{32}_{16}Y + e^{-} + \overline{\nu}$ I think this what happens in a Beta Minus decay.

8. Ishaan94

Yeah

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