I. History of the Periodic Table Mendeleev Mosely

A. Dmitri Mendeleev Dmitri Mendeleev (1869, Russian) Organized elements by increasing atomic mass. Predicted the existence of undiscovered elements.

B. Henry Mosely Henry Mosely (1913, British) Organized elements by increasing atomic number. Fixed problems in Mendeleev’s arrangement.

Terms Periodic Law Properties of elements repeat periodically when the elements are arranged by increasing atomic number.

I. Organization Metallic Character Rows & Columns Table Sections The Periodic Table I. Organization Metallic Character Rows & Columns Table Sections

State of Matter Look at your periodic table Some chemical symbols are black, red, and blue Black – Solid Blue – Liquid Red – Gas

C. Columns & Rows Group (Family) Period

Periods Have the same number of energy levels Same number “shells” in a Bohr diagram!

Groups Have the same outer electron arrangement Same number of valence electrons!

A. Metallic Character Metals Nonmetals Metalloids

Metals Properties Lustrous (shiny) Malleable (can be hammered) Conduct heat and electricity

Metals Groups on Periodic Table: Group 1: Alkali Metals Group 2: Aklaline Earth Metals Groups 3-12: Transition Metals Lanthanides Actinides Some elements in groups 13-15

Nonmetals Properties: Poor conductors of heat and electricity Brittle Located upper right side of periodic table

Nonmetals Groups on Periodic Table: Group 17: Halogens Group 18: Noble Gases Non-reactive

Metalloids Properties: Some properties of metals and some properties of nonmetals Make good semiconductors

Metalloids Elements: B, Si, Ge, As, Sb, Te, Po, and At

Color Your Periodic Table Metalloids: Orange Alkali Metals: Green Alkaline Earth Metals: Brown Transition Metals: Purple Lanthanide Series: Red dot lower right corner Actinide Series: Blue dot in lower right corner Halogens: Pink Noble Gases: Yellow

B. Periodic Trends Group # = # of valence e- (except He) Families have similar reactivity. Period # = # of energy levels 1A 2A 3A 4A 5A 6A 7A 8A

C. Dot Diagrams Dots represent the valence e-. EX: Sodium EX: Chlorine