What's the deal with the periodic table?
The periodic table is basically just a list of all the elements that we know about. Because of the way it's set up, we can use it as a reference source for figuring out all kinds of information.
What are the important parts of the periodic table?
1. Metals, nonmetals, and metalloids:
To review: Metals are conductors of heat and electricity, malleable, ductile, and generally solid. Nonmetals may be solids, liquids, or gases, and are poor conductors of heat and electricity. When solids, they are brittle, non-lustrous materials. Metalloids are solids at standard conditions, and are semiconductors of electricity, making them handy for use in the electronics field. Metalloids have properties between that of metals and nonmetals, causing them to have the nickname of "semimetals."
2. The families of the periodic
What else can I do with the periodic table?
Boy, am I ever glad you asked! You can find the electron configurations of any element using the periodic table by remembering that the two rows at the far left are S rows, the transition metals in the middle are D rows, the main block elements to the right are P rows, and the lanthanides and actinides are F rows. Likewise, the first S orbital you write down will be the 1s orbital, the first P orbital you write will be the 2p orbital, the first D orbital you write will be the 3d orbital, and the first F orbital you write will be the 4f orbital. If you're not too clear about how this works, take a look at a periodic table that has the electron configurations written out and see if it doesn't make a bit more sense.
You can use the periodic table to figure out which elements are most electronegative. (Electronegativity is a measurement of how much elements try to steal electrons from other atoms they're bonded to.) Electronegativity increases as you move from the left side of the table to the right side because elements on the right want to gain electrons to be like the nearest noble gas. Electronegativity decreases as you move down each family because of the shielding effect (inner electrons tend to shove the outer ones away, so the more electrons you have, the less tightly-bound the outer electrons).
Atomic radius increases as you move down each family (there are more energy levels) and decreases as you move from left to right (because the nucleus gets more positive charge but the electrons keep the same amount of energy all the way across).
For more detailed information about periodic trends, click HERE.