"This was the first two hour session that I've had with this student, and it was extremely productive. We went through her textbook to look at topics that she can expect to see on the chemistry subject SAT test that she will take in May. We went in order from the beginning of the book to try and cover material that she had gone over in class, but this time with more depth. For instance, when we covered atomic theory at the beginning of our sessions together, we went over things like the Bohr model of the atom, but we didn't go over quantum numbers. As we go through this book we will cover material much more thoroughly than she would have done so in class.
Atomic numbers can describe the states of each electron that exists in an atom. There are four different numbers: n, l, mL, mS. They all have rules of what they can equal:
The principal quantum number n=1,2,3,... where the number is the orbital that the electron is in. If the electron is in the 1s shell, then n =1. If the electron is in the 3p shell then n=3.
The angular quantum number l = 1, 2, 3, ..., n-1 corresponds to which type of orbital the electron resides in. l=0 corresponds to an s orbital, l=1 corresponds to a p orbital and so on.
The magnetic quantum number mL= -l to l describes the specific electron pair within the orbital described by l. In the s shell there is only one orbital, where two electrons are housed. In the p shell there are three electron pairs, described by mL= -1, 0, 1, where -1 is the left pair, 0 is the center pair, and 1 is the right pair.
The spin quantum number ms= -_ or +_ describes if the electron has an up or a down spin.
The other very large topic that we went over was radiation. Radiation is the breaking down of a particle's nucleus which sends one of three particles away from the atom:
1) alpha particle (a helium isotope) which is a helium atom with two extra neutrons
2) beta particle (a stream of electrons)
3) gamma ray (a high energy wave which can travel very far)
We discussed these particles, and looked at examples of chemical reactions which produced these particles. We also looked at the history of radiation. We discussed many other topics such as particle size, atomic radius, as well as the history of the periodic table. This brought us to the end of the session."