Question

Question #59da9

Answer 1

Here's what I got.

Explanation:

The incomplete nuclear equation given to you

`""_ 19^42"K" -> ""_ (-1)^(color(white)(-)0)"e" + ?`

describes the beta decay of potassium-42. You can tell that this is the case because the radioactive nuclide emits an electron, also known as a beta particle.

In beta decay, a neutron located inside the nucleus is converted to a proton. When this happens, the nuclide emits a beta particle and an electron antineutrino, `bar(nu)_3`.

As a result of the beta decay, the atomic number of the nuclide increases by `1` and the mass number of the nuclide remains unchanged.

This means that the balanced nuclear equation that describes the beta decay of potassium-42 looks like this

`""_ 19^42"K" -> ""_ 20^42"Ca" + ""_ (-1)^(color(white)(-)0)"e" + bar(nu)_e`

Notice that you have

• `42 = 42 + 0 ->` conservation of mass
• `19 = 20 + (-1) ->` conservation of charge