And since this negatively charged region is closer to each proton than the other proton is, the attraction to this region will overcome the repulsion from the other proton. Now the protons in this scenario will still repel each other, but they'll both be attracted to the negatively charged region that lies between them. As a result, the electrons will tend to spend more of their time in between the two protons, instead of each one quorbiting its own proton. As a result, it becomes attracted not only to its own proton, but to the proton of the other atom as well. The electron in each atom starts to notice the proton of the other atom. The situation looks like this *:īut an interesting thing can happen when the two atoms get close together. Typically, the electron is in its lowest possible energy state, that is, its ground state. Each of these has one electron, which quorbits a nucleus consisting of just one proton. Covalent bondsLet's start out with a relatively simple case. And that means that we have to look again at the electric charge in atoms. So when two atoms are attached (bound) to each other, it's because there is an electric force holding them together. It has no effect on electrons, and in fact, it has no effect outside the nucleus. But remember that the strong force has a very short range. And by now you're learned that, where atoms are concerned, there are two forces that are important: the electric force and the strong force. In physics, we describe the interaction between two objects in terms of forces. So if you really want to understand atoms, you need to understand how atoms interact with other atoms.

(Over 10,000,000,000,000,000,000,000,000 of them in a glass of water!) And in most substances, such as a glass of water, each of the atoms is attached to one or more other atoms. Of course, the problem with knowing about an atom is that one atom is a very rare thing. How Atoms Hold Together How Atoms Hold TogetherSo now you know about an atom.

Atoms join together to form what