Chemistry Notes 2011/2012 Ms. Feffer

Chemistry Notes Question: Question: How is an element different from a compound? Answer: Element = Compound =  Answer:  made up of only one pure substance. (periodic table)  is composed of two or more elements that are chemically combined. Example- Water (H 2 O) Example- Water (H 2 O)

Chemistry Notes pure substance  is a substance in which every particle of that element is the same. Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found

Chemistry Notes  Elements  Every element has a unique set of properties. The Periodic Table of Elements is arranged according to these properties.

Chemistry Notes physical properties Chemical properties  are used to classify elements are boiling point, melting point, color, and density.   used to separate elements from each other including flammability, reactivity with acids, or reactivity with oxygen.

Elements Are Grouped by:  Elements are identified by 3 main categories  Metals  Nonmetals  Metalloids

Elements Are Grouped by: Metals  They are all grouped together on the left hand side of the Periodic Table.  Not all metals are exactly alike, but they do have some properties in common.  **Metals are elements that are usually shiny and good conductors of electricity and heat.

Elements Are Grouped by: Metals  Metals are also malleable (can be hammered into thin sheets).  Metals are ductile, or can be drawn into thin wires.  Examples: Iron (Fe) and Copper (Cu).

Elements Are Grouped by: Nonmetals  Usually dull and poor conductors of heat and electric current.  Tend to be brittle and unmalleable.  Nonmetals are located to the right of the “zig zag line” on the Periodic Table.  Examples: Neon (Ne) and Carbon (C)

Elements Are Grouped by: Metalloids  Share properties of both metals and nonmetals.  Can be shiny or dull.  Somewhat malleable and ductile.  Examples: Silicon (Si) Arsenic (As). Silicon (Si) Arsenic (As).

Non- Metals Metals are located to the left, non metals to the right and metalloids touch both side of the “zig zag” line on the periodic table. Metals are located to the left, non metals to the right and metalloids touch both side of the “zig zag” line on the periodic table. Metals Metalloids

Compounds you need to know! Compounds Familiar Compound Compound Elements Combined Table Salt (NaCl) Sodium and Chlorine (Na + Cl) Water (H 2 O) Hydrogen and Oxygen (H + H + O) Hydrocloric Acid (HCl) Hydrogen and Chlorine (H + Cl) Carbon Dioxide (CO 2 ) Carbon and Oxygen (C + O + O) Methane (CH 4 ) Carbon and Hydrogen (C + H + H + H + H) Baking Soda (NaHCO 3 ) Sodium, Hydrogen, Carbon, and Oxygen (Na + H + C + O + O + O)

*Remember* Properties of Compounds  Compounds, like elements, can be identified by their own physical and chemical properties.  The compound Water is composed of Hydrogen and Oxygen chemically bonded together.