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Meet the Periodic Table

The Periodic Table is an essential tool for chemists. I have provided a simple version here. It shows the symbols, atomic numbers, and average atomic masses for each element. If you point at a symbol, it will show the element name. You can search for an element by name or symbol and it will be highlighted so it's easy to find.

How do you use the periodic table? It can help you predict many important properties of elements. To make these predictions, you will need to know a little about the different families or groups, which are the columns of the table. The term for the rows is period. Here is some info about the important groups.

group numberfamily namedescription
1Alkali Metalssoft, extremely reactive metals, valence 1, almost always ions: M+
2Alkaline Earth Metalssoft, less reactive metals, valence 2, almost always ions: M2+
13Boron Groupnon-metals and metals, valence 3
14Carbon Groupnon-metals and metals, valence 4
15Pnictogensnon-metals, valence 3
16Chalcogensnon-metals, valence 2, often X2– ions
17Halogensnon-metals, very reactive, volatile elements, valence 1, usually X ions
18Noble Gasesvery unreactive monatomic gases, valence 0
3-12Transition Metalsmetals with multiple valences and ionic forms, initially hard to fit into periodic table, many exist as M2+
*, **Rare Earth Metals(lanthanoides, actinoides) similar to each other, most have M3+ ionic form

To learn your way around the table, try going to this much fancier periodic table. Notice how metals are on the left and bottom of the periodic table, while non-metals are on the right and top. Metals are shiny, and they conduct heat and electricity. Non-metals don't conduct, and are often softer or easier to break than metals. Some elements are called metalloids because they are in between metals and non-metals, and you can see that the metalloids are also in between the metals and non-metals in the periodic table. The most reactive elements are on the edges of the table (groups 1 and 17), and the most reactive non-metals are O and F, in the top right corner.

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Last modified: Wed Mar 5 13:25:25 KST 2014