CHEMISTRY (from Egyptian kēme (chem), meaning "earth")

is the science concerned with the composition, structure, and properties of matter, as well as the changes

it undergoes during chemical reactions.

       SAFETY LABORATORY SYMBOLS

The Atom

The atom is the smallest unit of an element that retains the chemical properties of that element. An atom has an electron cloud consisting of negatively charged electrons surrounding a dense nucleus. The nucleus contains positively charged protons and electrically neutral neutrons. When the number of protons in the nucleus equals the number of electrons, the atom is electrically neutral; otherwise it is an ion and has a net positive or negative charge. An atom is classified according to its number of protons and neutrons: the number of protons determines the chemical element and the number of neutrons determines the isotope of that element.              http://en.wikipedia.org/wiki/Atom

The Periodic Table of elements

Dynamic Periodic Table

 LINK TO WebElements.com

Wooden Periodic Table:  http://www.theodoregray.com/periodicTable/

Sing the elements song by Tom Lehrer

and now by a 4 year old....

Element 

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons.       http://en.wikipedia.org/wiki/Chemical_element