Chemical Reactions UNIT 2 Chapter 4: Developing Chemical Equations Chapter 5:Classifying Chemical Reactions Chapter 6:Acids and Bases

Chemistry Review (Pages 134-135) There are 32 elements that you will commonly use throughout the chemistry unit. Metals Iron Nickel Copper Zinc Bromine Silver Tin Iodine Gold Mercury Lead 92. Uranium Fe Ni Cu Zn Br Ag Sn I Au Hg Pb U Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon H He Li Be B C N O F Ne 11. Sodium 12. Magnesium 13. Aluminum 14. Silicon 15. Phosphorus Sulfur Chlorine Argon Potassium Calcium Na Mg Al Si P S Cl Ar K Ca Copyright © 2010 McGraw-Hill Ryerson Ltd.

Chemistry Review (Pages 134-135) Click the “Start” button to review the formation of ions and ionic compounds. Ions are charged particles formed after the loss or gain of one or more electrons. Copyright © 2010 McGraw-Hill Ryerson Ltd.

Chemistry Review Metals (Pages 134-135) The metals are: Good conductors of heat (used in pots and pans) Good conductors of electricity (used in wires) Lustrous (used in jewelry and other ornamental objects) Almost all are solids (except for mercury) Malleable (can be hammered into sheets) Ductile (can be drawn into wires) Examples: Gold, Aluminum, Silver, Copper, and Sodium Copyright © 2010 McGraw-Hill Ryerson Ltd.

Chemistry Review Non-metals (Pages 134-135) The non-metals are: Poor conductors of heat (used as insulators in construction) Poor conductors of electricity (used to insulate wires) Non-lustrous (dull in appearance) Either solids, liquids, or gases (there are examples of each) Brittle in the solid state (break easily when hammered) Non-ductile (cannot be drawn into wires) Examples: Phosphorus, Sulfur, Chlorine, and Neon Non-metals Copyright © 2010 McGraw-Hill Ryerson Ltd.

Chemistry Review Metalloids (Pages 134-135) Metalloids have properties of both metals and non-metals. The metalloids show the largest variance in properties of any group in the periodic table. They can be metallic or non-metallic, malleable or non-malleable. The most notable members of this group are silicon and germanium, which have brought about revolutionary changes in the semiconductor industry. (Semiconductors normally will not conduct electricity but can be induced to do so at elevated temperatures or when they are mixed with trace amounts of other elements.) Metalloids Examples: Boron, Silicon, Arsenic, and Antimony Copyright © 2010 McGraw-Hill Ryerson Ltd.

Chemistry Review (Pages 134-135) Let’s review the use of the periodic table of the elements and how to read the information found within it. Ion Charges Atomic Number Element Symbol Element Name Atomic Mass Copyright © 2010 McGraw-Hill Ryerson Ltd.

Anatomy of an Atom The outermost shell is called the valence shell. The electrons in the valence shell are called valence electrons. The atoms of elements in Period 1 have one shell. This shell contains a maximum of 2 electrons. The atoms of elements in Period 2 have two shells. The valence shell contains a maximum of 8 electrons. The atoms of elements in Period 3 have three shells. The valence shell contains a maximum of 8 electrons. Recall: The atomic number represents the number of protons in the nucleus of an atom. The number of electrons is equal to the number of protons. Electron shells are fixed regions around the nucleus where the electrons orbit. electrons The nucleus of the atom is a region where protons and neutrons are found.

Worksheets– Practice with Electron Shells Take the next 10 minutes to complete the worksheet called “Electron shells for the first 20 elements in the periodic table”. When you are done the first worksheet, complete “Electron Shells”.

Patterns and Trends in The Periodic Table Atoms join together with bonds (a chemical joining) to form molecules. e.g. H and O join chemically to form H2O The physical and chemical properties of individual atoms are different from those of the compounds they form. ie. H and O have different properties than H2O Understanding how the periodic table is arranged can predict how elements join together. For example Na and Cl join to form a new compound with the formula NaCl. Group 1 Group 18 Period 1 Period 2 The “staircase” line separates the elements into metals and non-metals. Period 3

Using Electron Dot Diagrams to Represent Valence Shell Electrons A simple model called an electron dot diagram (or Lewis Diagram) is used to represent an atom and its valence electrons. The symbol of the element is used to replace the nucleus and the inner shell electrons. The electrons from the valence shell are shown as dots placed around the symbol. Examples: