Chemical Periodicity Chapter 14

History of the Periodic Table Mendeleev (1860’s) Developed the first periodic table It was arranged by atomic mass He was able to predict properties of elements

History of the Periodic Table (cont.) Moseley – developed the modern periodic table

Characteristics of Metals Hard Shiny Conduct heat and electricity well Includes the transition and inner-transition metals Inner transition metals include the lanthanoids and actinoids

Characteristics of Nonmetals Are gases or brittle solids at room temp. Surfaces are dull Insulators

Characteristics of Metalloids Have properties of both metals and nonmetals

I. Periodic Table Revisited Groups or Families (terms synonymous) vertical columns have similar chemical & physical properties B. Periods Horizontal rows Energies of outermost electrons are similar

Period vs. Group Period All elements in a horizontal row 7 periods on the periodic table

Group All elements in a vertical column Sometimes called “families”

Group 1 (IA) – Alkali Metals

Group 2 (IIA) – Alkaline Earth Metals

Group 17 (VIIA) - Halogens

Group 18 (VIIIA) – Noble Gases

II. Organization (your Roadmap) A. Metals- Nonmetals- Metalloids- Left of zig zag Right of zig zag On the zig zag NONMETALS METALLOIDS METALS

REPRESENTATIVE “Group A” C. Group A & B Group A- Representative Group B - Transition REPRESENTATIVE “Group A” TRANSITION “Group B” INNER TRANSITION