Periodicity (sorry for delay)

Ok so this will be the first of three posts today... I'm obviously just an idiot who cannot get a post done on time, and it has made me have to do 5 total posts :(.

The periodic table is really organized in a cool way. Atoms in the same rows and columns relate to each other in certain ways. This is called periodicity.

We discussed two characteristics today that follow patterns (and touched on a third). They are as follows:

Atomic Radius: Atomic radius is a manner of measuring atomic size. This is measured by taking the distance between nuclei of two atoms of the same type, and dividing that by two. So which ones are the biggest? That can be determined by where they located on the periodic table. By a rule of thumb, elements get smaller when you go across the periodic table, before jumping back up when moving on to the higher energy level. Why? When going up an energy level, the valence set is farther away, so that is why it increases as going down. When going across, the size depletes because with more protons, the positive charge pulls stronger.

First Ionization Energy: This is the amount of energy needed to get take an electron away from the element. It takes less energy to take elements on the bottom and left of the table, which is pretty easy to understand. Left elements only need to "lose" one element to become at a full valence level, so they naturally give them up easy. The ones on the bottom are even easier, because the valence level is so far away from the nucleus. That is obvious the reason why alkali metals (especially Francium) react so violently:

ElectroNegativity: This is the opposite of Ionization energy: How likely it is to gain an atom. It is based on a scale of 1-4, with 4 being the highest number. The lower the energy level and the farther right an element is (not counting the Noble Gases, which do not gain an electron), the higher the number. The reasons for this are obvious if you've read the rest of this post: the lower the energy level, the more proton pull, and elements on the far left want to gain an electron for a full valence level. Only one element has an electronegativity rating of 4: fluorine. So what happens when you put fluorine and francium together? Big big big boom.

So now you know about some periodic characteristics. Now, I will start to write on some more chemistry. The next scribe is: ME!!!!!!!!!!!!