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The Periodic Table

Terms and Definitions

Introduction to the Periodic Table

A Short History of the Periodic Table

Atom  -  The smallest unit of matter that can exist of an element.
Compound  -  A molecule containing two or more different atoms bound together.
Element  -  A fundamental substance that has a unique atomic number on the periodic table.
Gas  -  A form of matter that has mass but no definite shape, and can be either compressed or expanded to fill an infinite volume.
Isotope  -  A different form of an element that varies by the number of neutrons in the nucleus.
Liquid  -  A form of matter which has mass, occupies a volume, and flows to adopt the shape of its container.
Solid  -  A form of matter which has a definite shape and volume.

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