DOR: Chemical/Physical Change 9/4/13 Classify each change as either chemical or physical. 1) Salt crystals are pulverized using a mortar and pestle 2) Sodium bicarbonate is dissolved in water 3) Gasoline in your engine burns as you start the car 4) Blood is separated in a centrifuge 5) Fireworks

Periodic Table A General Overview

The Periodic Law Dimitri Mendeleev (1869/1871) was the first scientist to publish an organized periodic table of the known elements. He was taking a chemistry course in Russia and tried to find a way to organize the periodic table.

The Periodic Law Mendeleev even went out on a limb and predicted the properties of 2 at the time undiscovered elements. He was very accurate in his predictions, which led the world to accept his ideas about periodicity and a logical periodic table.

The Periodic Law Mendeleev understood the ‘ Periodic Law ’ which states: When arranged by increasing atomic number, the chemical elements display a regular and repeating pattern of chemical and physical properties.

The Periodic Law Groups/Families Elements with similar chemical properties and behavior appear Vertical columns in periodic table Periods horizontal rows on periodic table Fairly predictable change in chemical/physical properties. Lanthanide/Actinide series Found under the main table Actually fit between atomic numbers 57 and 89

Metals, Nonmetals, Metalloids

There is a zig-zag or staircase line that divides the table. Metals are on the left of the line, in blue. Nonmetals are on the right of the line, in orange.

Metals, Nonmetals, Metalloids Elements that border the stair case, shown in purple are the metalloids or semi- metals. There is one important exception. Aluminum is more metallic than not.

Metals, Nonmetals, Metalloids How can you identify a metal? What are its properties? What about the less common nonmetals? What are their properties? And what the heck is a metalloid?

Metals Metals are shiny, malleable, ductile, and are good conductors of heat and electricity. They are mostly solids at room temp. Exception: Mercury

Nonmetals Nonmetals are the opposite. No color, no shine They are dull, brittle, nonconductors (insulators). Gases at room temperature Some are solid at room temperature (C, P, Se, S, I)

Metalloids/Semi-Metals Metalloids, aka semi-metals are just that. They have characteristics of both metals and nonmetals. They are shiny (like metals) but brittle. Solids at room temperature And they are semiconductors. “on the fence, middle of the road” B, Si, As, Te, At, Ge, Sb, Po

Noble Gases Group 18 Do NOT react with other elements Unusual elements Gases at room temperature Ne, Ar, Kr, Xe, Rn, He

Writing Prompt Medeleeff developed the arrangement of the periodic table while in a chemistry class in school and assigned the task of placing the element properties together. If you were given this task before the table was developed, how would you go about arranging the elements? Write one paragraph explaining of why and how you would arrange this element table. Draw a diagram of your table. Your explanation and drawing must be logical ! Be creative!

Classwork: Metal Identity Identify each element as a nonmetal, metal, or metalloid 1) Na6) Cl 2) P7) Mg 3) Se8) Al 4) Ge9) Sb 5) N10) Si

Homework Read pp Problems p. 22 # 19-21