Atomic Structure

We hear about atoms all the time. Everything we've ever known and loved is filled to the brim with atoms. However, what do atoms exactly look like? Well, due to some rules in quantum physics, we can't tell you exactly what atoms look like but can give a model.

At the center of each atom is a nucleus. Every element except hydrogen(only a proton) has a nucleus containing of one or more neutrons and multiple protons. Neutrons don't have charge so they are attracted to protons through the nuclear strong force, not the electric force. Electrons orbit the nucleus and are attracted electrostatically to the protons in the nucleus. This is because like charges repel and opposites attract. Electrons are negative and protons are positive while neutrons have no charge. Thus, electrons are attracted to protons but repelled by other electrons. This also means that when you add an electron to a neutral atom, the ion formed will have a negative charge. In contrast, this also means that when you remove an electron from a neutral atom, the ion formed will have a positive charge.

However, electrons don't just orbit anywhere they please. They can only orbit the nucleus in what are known as quantized orbits, orbits of integer level. They can't orbit outside these orbits or between them. The quantization levels can move themselves depending on what happens to the atom(like ionization) but the electrons must stay within these levels. The principal quantum number is just the number that refers to the electron orbit level, usually denoted by n. As n increases, the energy increases for the electrons. However, don't let this confuse you. While the energy for the electrons increases, their attractions weaken. If this makes no sense, think of it like this. The number -8 is greater in value than -32. However, -32 is greater in magnitude than -8.