Periodic Table

A periodic table shows most of the elements known -- depends upon when the table was prepared as to how many are there. The letters in the boxes of the table show are the symbols for the elements which come from either the original names or the current names. Some examples are below:
Current NameOriginal NameSymbol

I don't recommend that you try to memorize all of the original names, but just to memorize the element symbols for each of the elements. Fortunately many of them are easy like H,He,Li,Be,B,C,N,O,F,Ne. You might notice that I just went through the first two rows of the periodic table.

help Here is an excellent Periodic Table

The numbers above the symbols are the atomic numbers (number of electrons which is equal to the number of protons) of the elements. Remember that I said that the chemical properties of the elements are determined by the electrons? Good. Now you can know why the elements are arranged the way that they are. All of the elements in a particular column have very similar chemical properties. We will see why that is later when we learn more about the electronic structure of the elements. These columns are called groups or families. The rows are called periods.

Looking at a periodic table like the one above, you will see that there are also descriptive names for sets of the elements: alkali metals, alkaline earth metals, transition metals, non-metals, halogens, noble gases, lanthanides, and actinides. You will see that most of the elements are metals. The noble gases have very little chemical reactivity. It was not until about 1962 that the noble gases were found to be chemically reactive when XeF4 was discovered. Metals tend to lose electrons to form cations, conduct heat and electricity, be malleable (easily formed), and tarnish easily. Nonmetals tend to gain electrons to form anions.

Some of the elements actually exist as diatomic molecules(or diatomics). The diatomics are H2, N2, O2, F2, Cl2, Br2, I2, and At2. You will need to memorize these.

Also note the numbers above each column like IA, IIA, etc. The Group IA metals all form +1 cations and the Group IIA metals all form +2 cations. You will learn more about the periodic table as we continue our study.

Now take a practice quiz to help you understand if you understand the basic concepts.
You must use your real name when it asks for a name.
The test will only submit when you have answers all of the questions correctly.
If you are not taking this course for credit please do not answer all the questions correctly for I don't want to be flooded with email answers to the tests.

Web Author: Dr. Leon L. Combs
Copyright 2000 by Dr. Leon L. Combs - ALL RIGHTS RESERVED