Now of course 2.04 x 10 -11 is a very small number. Solve for 'E' and you find that the binding energy in that oxygen nucleus is 2.04 x 10 -11 joules, with the negative sign indicating that the energy is being released. This ingenious little equation relates mass and energy by a simple proportionality constant, and thanks to Einstein we know that constant is the square of the speed of light, or c 2. To find out how much binding energy that missing mass amounts to, you can use it as the 'm' in Einstein's formula. It's the energy that holds the nucleons together so for example the mass defect for an oxygen atom is negative 2.269 x 10 -28 kilograms. That 'missing mass' in the nucleus, known as its mass defect, is actually present in the form of energy. Specifically the mass of the nucleus, exactly 15.99 atomic mass units, is lower than the mass of its individual nucleons put together, in this case 16.13 amu's. If you were to add up all the individual masses of all sixteen nucleons separately and then compare that to the total mass of an actual oxygen nucleus, you'd find that there's a difference between the two. Collectively, by the way, these particles are known as nucleons. To tease it apart consider the nucleus of an atom of oxygen, eight protons and eight neutrons. Okay, there is a lot there, in what I just said. (Crash Course Intro)Į = mc 2 is formally known as the mass-energy equivalence formula and it states that mass is interchangeable with energy. It explains one of the most powerful sources of energy known to humanity. Part of why it's so famous, I like to think, is because the logic behind it is so elegantly simple and yet totally counter intuitive, but it's probably also famous because it's important. Probably the most famous equation in the world and since it was first hit upon by a young patent clerk in 1905 it has become synonymous with scientific genius. The binding energy of an atom is calculated with the formula E = mc 2. Now I'm not going to lie to you, nuclear chemistry is terribly complicated, but we have a way of understanding it that, while not exactly simple, is one I'm sure you've heard of. It's actually what we mean when we talk about nuclear energy. This is known as binding energy and it's one of the fundamental principles of nuclear chemistry. And the amount of energy, that holds each proton or neutron in an atom's nucleus, is the same amount that's released when it's removed.

Stability really, is kind of just a way of saying, it can exist. If the nucleus is going to break apart, then that's not going to be something that lasts very long. But what is this illusive stability that all things seem to be striving for exactly? In nuclear chemistry it simply has to do with keeping the nucleus together. As I said before chemistry is, like many aspects of your own life, all about a search for stability. Last week we talked about radioactive decay and how atomic nuclei get rid of various particles in order to become more stable.

Fission example chemistry