The next track will take eight atoms. Atoms are often drawn as if they were small solar systems, but the electrons do not move in a flat plane. Each of the elements has a different number of the tiny electrons, and a corresponding size of nucleus. Hydrogen is the smallest, with only one electron. Carbon, nitrogen, and oxygen, are also small, light atoms.
Atoms combine to fill up the spaces in their shells so that the outer shell is complete.
Let's see how that works. This is a diagram of an atom of neon gas. I have colored the nucleus orange and the electrons blue. The inner shell is filled by two electrons. Neon doesn't need any more electrons to fill its outermost shell, so it doesn't participate in chemical reactions.