Electro- negativity is how badly atoms want electrons. The most electronegative atoms are Fluorine, Chlorine, and Oxygen. Everyone wants to be a Noble Gas... and halogens are the closest so they are the most electronegative. Ionization energy is how difficult it is to remove electrons. It is difficult to remove electrons from atoms that are electronegative.
Atomic radius increases as you move down the periodic table because atoms have more mass, but actually decreases from left to right because atoms are holding on to their electrons tighter (because they are more electronegative).
Shielding has to do with how protons are blocked by the electron shells - the more shells there are, the more blocking there is. So something in period 5 (with 5 shells) has more shielding than an element in period 2 with two electron shells. Sheilding is constant across the periodic table because the number of shells is constant.
If you were absent for the Physical versus Chemical lab, you can make up the majority of it by following the link below and watching YouTube videos of the experiments. You can also just check them out because they are cool.
Open a link in a new tab. In the blue box, look for "Play Games" and "Scatter." You will then need to drag the names to the correct formula. If it disappears, you matched it correctly. Play each set a couple of times until you get really good. You can also use these as flashcards and make up and take tests.
Click on the rice above to test your knowledge of the Periodic Table while earning rice for the United Nations World Food Program. You can also test your knowledge of vocabulary as an excellent SAT prep.