The first version of the periodic table was created by a Russian scientist, Dmitri Mendeleev in the 1860’s.

Main Parts of the PTE: Metals: found to the left of the “ladder” generally shiny solids and good conductors The position of elements in the periodic table provides hints about the types of compounds they form.

The periodic table has been shortened horizontally by moving the 4f and 5f (inner transitional elements) below the main body of the table.

Non-Metals: found to the right of the “ladder” exist in all three states of matter dull, mostly insulators

Metalloids: found along both sides of the “ladder” have properties of both metals and non-metals

Horizontal rows are called periods.

Vertical columns are called groups or families.

These families tend to have similar physical and chemical properties. Chemical families: - alkali metal (Group 1) - alkaline earth metals (Group 2) - noble gases (18) - halogens (17)

Hyperlink to NEW periodic table song!

How to read the Periodic Table: # of protons = = # of protons + neutrons

Atoms are the building blocks of elements. They are made up of three subatomic particles: 1) protons – are found in the nucleus and have a positive charge. 2) neutrons – are also found in the nucleus, but have no charge. 3) electrons – orbit around the nucleus and have a negative charge.

Electrons can jump through space and change the charge on an atom. When the number of electrons equals the number of protons the atom will have no charge (neutral atom) = electrons p p = protons = neutrons p

What if an atom does not have the same number of protons and electrons? It has formed an ion, a charged atom in which the number of electrons is different from the number of protons.

When the number of electrons is greater than the number of protons the atom will have a negative charge (Anion) = electrons = protons p p = neutrons p

When the number of electrons is less than the number of protons the atom will have a positive charge (cation) = electrons = protons p = neutrons p p

Let’s determine what element this is! # of protons: # of neutrons: # of electrons:

Atomic Number = # of protons Atomic Mass = # of protons + # of neutrons

Representation: Atom Charge (if any) Atomic Mass C 12 6 Atomic #