1.  Write the short hand configurations for the following elements: ◦ Molybdenum, Selenium, Strontium, Ruthenium, and Antimony  Write the number of valence electrons the previous elements have  Based on its group, how many valence electrons will Bromine have? Prove this.  Draw the electron dot diagram for Oxygen and Silicon

2. The Periodic Table Pg.45

3.  http://www.youtube.com/watch?v=0RRVV4Di omg http://www.youtube.com/watch?v=0RRVV4Di omg

4.  Only knew 23 elements in 1790  Discovery of electricity brought change  Dmitri Mendeleev demonstrated a connection between atomic mass and elemental properties (1869)  Saw a repeating pattern  Left blank spaces where undiscovered elements should go (Sc, Ge, and Ga)  Henry Moseley rearranged the table according to atomic number  A clear repetition of repeating physical and chemical patterns emerged. Called periodic law

5.  The columns on the periodic table are called groups (or families) ◦ Elements in the same group have similar chemical and physical properties  The rows are called periods  Main group elements (representative elements): Groups 1-2, 13-18  Transition elements: Groups 3-12  Sometimes see a number/letter system  Can find elements based on group and period

6.  There are 3 major groups on the periodic table: ◦ Metals ◦ Nonmetals ◦ Metalloids (or semiconductors)

7.  The metals are on the left side of the periodic table  Malleable and ductile  Shiny  Good conductors of heat and electricity  They further broken into 4 categories ◦ Alkali metals ◦ Alkaline Earth metals ◦ Transition elements ◦ Inner transition elements

8.  Are on the right side of the stair-step (except H)  Can be gases  Brittle and dull  Poor conductors of heat and electricity  Br only nonmetal that is a liquid at room temp  Can be broken into smaller categories ◦ Halogens ◦ Noble gases ◦ Carbon group

9.  Border the stair step line  Have properties of both metals and nonmetals  Si and Ge most important as they are used in computer chips