In Lesson 24, we went back to idenfitying patterns within the periodic table and discovered that it's divided into four sections: an "S" block, a "P" block, a "D" block, and an "F" block. S, P, D, and F are letters chemist use to describe the subshells of electron shells within an atom. If that doesn't make sense, subshells are essentially the smaller rings (the "clouds" of space) between the official shell rings, which we typically see in Bohr models. Here's a nifty illustration of that, where blue rings represent the official shells:
Easier? I hope.
The S subshell can hold up to 2 electrons, the P up to 6, the D up to 10, and the F up to fourteen. The F block/subshells are the lanthanides and actinides on the periodic table. You know how many subshells an atom has by where it's located on the periodic table. For example:
- Period 1: S subshell, nothing more
- Period 2: S and P subshells
- Period 3: S and P subshells
- Period 4: S, P, and D subshells (you have now included the transition metals, the "D" block.
- Period 5: S, P, and D subshells
- Period 6: S, P, D, and F subshells (the lanthanides would be found in period 6. Include the F shell)
- Period 7: S, P, D, and F subshells (the actinides are here; include the F shell.)
As you can see, as your period # increases, you have more shells and subshells, and that means that you have bigger atoms, which is why elements in the lanthanides/actinides, like Uranium, are so unstable and decay.
You can write how many electrons lie in each subshell like so:
- [Element symbol] 1s^2s^2p^3s^3p^4s^4p^4d^
As stated in one of my earlier summaries, the ^ symbol stands for the superscript, in this case the number of electrons in the subshell. It is not to be confused with a coefficient, since it's written small and above the number.
Problems:
No comments:
Post a Comment