How do you write an equation for the beta decay of sodium-24?

1 Answer
Jun 16, 2017

Here's how you can do that.

Explanation:

Sodium-24 undergoes beta decay, or, more specifically, beta-minus decay.

During a beta decay, a neutron located in the nucleus of a radioactive nuclide is converted to a proton. At the same time, the nuclide emits an electron, also called a beta particle, and an electron antineutrino, bar(nu)_"e"¯νe.

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Since a neutron is being converted to a proton, you can say that the atomic number of the nuclide increases by 11 and the mass number of the nuclide remains unchanged.

You will thus have

""_ 11^24"Na" -> ""_ Z^A"?" + ""_ (-1)^(color(white)(-)0)beta + bar(nu)_"e"2411NaAZ?+01β+¯νe

In any nuclear reaction, charge and mass must be conserved, so you have

  • 24 = A + 0 ->24=A+0 conservation of mass

This will get you

A = 24 ->A=24 the mass number remains unchanged!

  • 11 = Z + (-1) ->11=Z+(1) conservation of charge

This will get you

Z = 12 -> Z=12 he atomic number increases by 11!

Therefore, you can say that the resulting nuclide will have Z = 12Z=12 and A = 24A=24. A quick look in the Periodic Table will reveal that you're dealing with magnesium-24.

This means that you have

""_ 11^24"Na" -> ""_ 12^24"Mg" + ""_ (-1)^(color(white)(-)0)beta + bar(nu)_"e"2411Na2412Mg+01β+¯νe