Question #59da9

1 Answer
Oct 8, 2017


Here's what I got.


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