Question

Question #a9f0d

Answer 1

`""_19^41"K"`

Explanation:

As you know, when a radioactive nuclide undergoes electron capture, an electron located in one of the inner shells is absorbed by the nucleus. In the process, a proton is converted to a neutron and an electron neutrino, `nu_"e"`, is emitted.

So right from the start, the fact that a proton is being converted to a neutron tells you to things

• the atomic number of the nuclide decreases by `1`
• the mass number of the nuclide remains unchanged

In your case, calcium, `"Ca"`, has an atomic number equal to `20`, which means that the resulting nuclide will have

`Z = 20 -1 = 19`

The element that has an atomic number equal to `19` is potassium, `"K"`. Since the mass number remains unchanged, you can say that the resulting isotope will be potassium-41.

So you can say that the nuclear equation that describes the electron capture of calcium-41 looks like this

`""_ 20^41"Ca" + ""_ (-1)^(color(white)(-)0)"e" -> ""_ 19^41"K" + nu_ "e"`

Notice that you have

• `41 + 0 = 41 " "" "->` conservation of mass
• `20 + (-1) = 19 ->` conservation of charge