Chapter 4

1. Chapter 4 Elements, Compounds & Mixtures Warning; the test for this chapter is one of the toughest

2. Section 1 - Elements • I. ELEMENTS (p.82-85) -An element is a pure substance that cannot be separated into simpler substances by physical or chemical means. Mercury iodine Gold http://mineral.galleries.com/minerals/elements/gold/gold.htm www.zyra.org.uk/ mercury3.htm http://www.lighthouse.chtr.k12.ma.us/periodic/periodicimages/iodine.jpg

3. A. An element has only one type of particle. • 1. A pure substance is a substance that has • only one type of particle. • 2. For example every particle (atom) in a 5 g • nugget of the element gold is exactly like • every other atom of gold in the nugget. http://www.uni-ulm.de/fkp/hilights/sep2002/bild2.gif

4. Every element can be found on the periodic table. If it’s not on the table on page 744. it’s not an element. • Is aluminum an element? • steel? • oxygen? • carbon dioxide? • Fluoride?

5. Section 1 - Elements B. Every element has a unique set of properties that allow you to identify it. ( Can you remember 6 of the 9 properties listed here?) • 1. Each element has it's own characteristic properties. • a. These properties do not depend on how much of the element is present. • b. Examples of characteristic properties include, boiling pt., melting pt. density and reactivity with acid. http://www.astro.su.se/~magnusg/large/Boiling_water.jpg

6. Section 1 - Elements 2. We identify elements by their properties. Physical properties such as color, hardness, and texture can also be used. • Even properties like flammability, reactive with oxygen and other unusual characteristics can be used. (These properties are not physical properties) Calcite- a rock that contains calcium compounds will glow under a “black light” http://disc.gsfc.nasa.gov/oceancolor/images/fluorescent_calcite_willemite.jpg

7. Section 1 - Elements • C. Elements are categorized by their properties. • 1. Elements are categorized into groups based on • their shared properties. For example Iron • nickel and cobalt are all shiny, conduct • thermal energy, and electric current. So they • are categorized as metals. Metals are not all • exactly alike but they have enough in • common to be in the same group. • (Most elements are metals) (Types of elements overhead) metals movie clip

8. Section 1 – Elements • 2. If you know what category an element belongs to you can predict the properties. • a. Metals- shiny, good conductors of heat and electric current, they are malleable (hammered into thin sheets), and ductile(drawn into thin wire). http://www.volcanoarts.biz/cart/wire/20ga-wire.jpg

9. Section 1 - Elements • b. Nonmetals- Dull (not shiny), poor • conductors of heat and electric current, • solid non metals are brittle (broken easily) and • unmalleable. Many are gases. • ( They are mostly found on the right side of the periodic table. There are only 17) • Non-metals clip

10. Section 1 - Elements • c. Metalloids- (also called semiconductors) • is elements that have properties of both • metals and non-metals. Some are shiny • while others are dull, they can be • somewhat malleable and ductile. Some • conduct thermal energy (heat) and • electric current. (There are only 8 metaloids) • http://www.quigmans.com/elements.swf • Metalloid movie clip