The periodic table of the elements.
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L.Gardiner/Windows to the Universe

The Periodic Table of the Elements

Everything you see around you is made of tiny particles called atoms, but not all atoms are the same. Different combinations of protons , neutrons and electrons make different types of atoms and these different types are called elements.

The picture to the left shows the periodic table of the elements. Scientists made this table as a way to organize all the elements that have ever been found or created.

Each element has its own symbol. For instance, the upper left square of the table is labeled ‘H’. The ‘H’ is the symbol for an element called hydrogen.

Notice how each element in the table has its own number. This is called the atomic number and shows us how many protons are in the nucleus of each atom of the element. It also tells us how many electrons are in a neutral atom of the element. For instance, the ‘1’ listed in hydrogen’s square indicates that each atom of hydrogen has one proton and one electron.

Each row in the table tells how many shells around the nucleus an element’s atoms have to hold electrons. For example, hydrogen (H), in the top row has one electron shell while Lithium (Li) in the row below, has two electron shells.

Of all the elements in the periodic table, only the first 92 are naturally found, while the others are synthetically made. The 92 natural elements are the ingredients used to make everything we find on Earth.

Last modified April 29, 2003 by Lisa Gardiner.

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