Introduction to the Periodic Table:  Parts of an Atom

An element is the simplest form of an entity that keeps its identity.  There are 118 elements in the Periodic Table.  Examples of some elements include hydrogen, gold, carbon, and zinc.  Elements may be in a gas, liquid, or solid state.

Each element is made up atoms that have protons, electrons, and neutrons.

Atomic Number—The atomic number of an element is the same as the number of protons in the nucleus (center) of an atom.

Proton—A proton is a positive particle in the nucleus of an atom. 

Electron—An electron is a negative particle in the ‘orbit’ of an atom.  An atom has an equal number of electrons and protons.

Neutron—Neutral particle in the nucleus of an atom. Most but not all elements have neutrons.

Symbol--Each element in the periodic table has a symbol, a letter or letters that identify the element; for example, the symbol for hydrogen is H, the symbol for gold is Au, and the symbol for zinc is Zn.