Numerical electron configuration
“How can we quantify electron configuration?”
When dealing with electron configuration, wouldn’t be usefull if we could somehow create a framework to conceptualize everything? As discussed earlier, the electrons of an atom are organized into shells and orbitals, the former dealing with the distance from the center of the nucleus, and the latter dealing within the probabilistic location To start off, we will assign a number to each of the atomic shells, with the first shell being called the “first shell”, the second the “second shell”, and so on. Furthermore, each of these shells will be divided into subshells. Subshells are the set of atomic orbitals that are most similar to each other. The first shell will have one subshell (called the 1s subshell), the second shell will have two (the 2s and 2p respectively), the third will have three (3s, 3p, and 3d), and so on. Each of the letters indicate a different orbital of the subshell. Each orbital can hold two electrons, and each subshell will be able to hold 4L+2 electrons, with L being the orbital value of the subshell (for example, the s subshell will have an orbital value of 0,the p a 1, and so on).
Now, how do we incorporate the change in electrons into this system? When electrons flow into an atom, they will enter the orbital with the lowest level of energy associated with it, as that is the easiest one to deal with. The two factors that affect the energy level are the shell and orbital value. As a result, it is possible to have an shell with a higher value but a lower orbital be filled before one with a lower value shell but higher orbital. For example, the 4s orbital will be filled before the 3d one since the 3d has a higher energy level. The pattern for this phenomena can be seen on the picture for this article.
Finally, this brings us to the outermost shell of the atom. If this shell, termed the valence shell by chemists, has a lack of filled space, then it will be able to react with other chemicals to create chemical reactions and make chemical bonds.