An element is a chemical made up of one kind of atom. The known elements are listed on a chart called the Periodic Table. The elements are not randomly placed on the table. Instead, they are listed in order of their atomic number. Each element has its own atomic number which identifies it from all the other known elements. For example, the atomic number for the element hydrogen, H,is 1. This means that all the atoms of hydrogen have the same atomic number, which is 1.
In the diagram, notice that the elements are arranged in numerical order from left to right, the same direction that you use when you write a sentence. Notice that there is a gap between Atomic No. 1, H, at the top left of the table and Atomic No. 2, He, at the top right of the table.
The names of each element are shown but they are too small to see in the diagram on this page. The letters in each box are codes for the element name. Some of the letters, like H for hydrogen, and He for helium are obvious, but a bit of decoding is needed for other elements, such as: Na = sodium, Fe = iron. This is what makes chemistry so much fun. You can write things in code–yea!!!
What makes one element different from the other elements? See Clue #1.