Here’s a simplified explanation.
The <em>protons</em> in the nucleus <em>repel each other</em>. The <em>neutrons provide the “glue”</em> that holds the nucleus together and prevents it from flying apart.
The “glue” is the strong nuclear force. It is strong but extremely short range. It falls off extremely rapidly as the p-n distance increases.
A <em>neon atom</em> has 10 protons. There are three stable isotopes, with 10, 11, and 12 neutrons.
With fewer than 10 protons, the glue is not strong enough to hold the nucleus together.
If there are more than 12 neutrons, the average p-n distance is great enough that the glue has again become too weak.
<em>Gold</em> has one stable isotope. It contains 79 protons and 118 neutrons.
If there are fewer than 118 neutrons, the proton repulsions will be too strong for the strong force. If there are more than 118 neutrons, the average p-n distance will be large enough that the glue will again be too weak to hold the nucleus toge
ther.
Salt water is a Homogeneous Mixture......
It is rinsed one last time with the solution to be measured because if there is water in the burret, then it could alter the results. Slightly, but it is still altering it.
