Question #a9f0d

1 Answer
Nov 2, 2017

#""_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

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