Balanced nuclear equation for carbon dating
So 234 plus four gives me a total of 238 on the right, and so therefore nucleons are conserved here.
In terms of charge, I know charge is also conserved. The identity of the other product, just look it up here at our table, find atomic number of 90, and you'll see that's thorium here. So we think about what's happening visually, we're starting off with a uranium nucleus which is unstable, it's going to eject an alpha particle, so an alpha particle is ejected from this nucleus, so we're losing this alpha particle, and what's left behind is this thorium nucleus.
In alpha decay, an alpha particle is ejected from an unstable nucleus, so here's our unstable nucleus, uranium-238.
So we're going to make protactinium here, so Pa. Well, 234 minus 90, 234 minus 90 gives us the number of neutrons. On the right, we have 91 protons, how many neutrons do we have? When we think about what else is made, we know that nucleons are conserved, so we have one nucleon on the left, one nucleon on the right. In terms of charge, if we have zero charge on the left, plus one on the right, we need negative one right here. You're also going to make an anti-neutrino, and that's just really not part of this video, so we'll just ignore it for now.
Trying to figure out the other product from our nuclear equation, I know nucleons are conserved, so if I have 238 nucleons on the left, I need 238 nucleons on the right.
Well, I have four from my alpha particle, so I need 234 more.
So here's our electron and an electron ejected from the nucleus is called a beta particle.
We could put a beta here, and it's an electron, so a negative one charge, and then a zero here. And a neutron is a nucleon, so we put a one right here.