1. Class Notes: The Periodic Table

2. Creation of the Periodic Table Mendeleev: arranged elements based on atomic mass -noticed holes in the table, so he predicted the existence and properties of undiscovered elements

3. Moseley: helped determine atomic numbers for elements -rearranged Mendeleev’s table so that it was based on atomic number, and this is how the modern periodic table is set up

4. The periodic table (P.T.) -arranged in rows (periods) and columns (groups/families) -grouped by physical and chemical properties -groups – each column has a number and a letter Ex. 1A, 2A, etc.

5. Group A = Representative Elements -metals, nonmetals and metalloids Group B = Transition Metals

6. Inner Transition Metals Metals – on the left and center of the P.T. and under the stairway -most elements are metals -high luster when clean -high electrical conductivity -mostly solids (Hg – liquid) -ductile (wire) and malleable (sheet)

7. Non-Metals – grouped on the right side, above the stairway -non-lustrous -poor electrical conductors -gases; liquids; brittle solids -H 2 is the one exception in position

8. Metalloids – have both properties (of metals and non-metals) -touch the stairway (except Al and At)