© 2003 mark s. davis ap chemistry chapter 2. © 2006 mark s. davis 5

© 2003 Mark S. Davis

AP Chemistry

Chapter 2

© 2006 Mark S. Davis

5

© 2006 Mark S. Davis

•http://dbhs.wvusd.k12.ca.us/webdocs/ChemTeamIndex.html

© 2006 Mark S. Davis

• A man was out walking in the desert when a voice said to him, "Pick up some pebbles and put them in your pocket, and tomorrow you will be both happy and sad."

• The man obeyed. He stooped down and picked up a handful of pebbles and put them in his pocket. The next morning he reached into his pocket and found diamonds and rubies and emeralds. And he was both happy and sad. Happy he had taken some - sad that he hadn't taken more.

• And so it is with education

© 2006 Mark S. Davis

Atomic Theory of Matter

• Dalton’s Postulates1. Each element is composed of

extremely small particles called

2. All atoms of a given element are identical; the atoms of different elements are different and have different properties (including different masses.)

© 2006 Mark S. Davis

Dalton

3. Atoms of an element are not changed into different types of atoms by chemical reactions; atoms are neither created nor destroyed

4. Compounds are formed when atoms of more than one element combine; a given compound has the same relative number and kinds of atoms.

© 2006 Mark S. Davis

Define

• Atom:–

• Element:–

© 2006 Mark S. Davis

Define• Compounds:

– Substance composed

• Mixtures:– Combination of two or more

• Law of conservation of Mass:

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Atomic Structure

• Protons:–

• Neutrons:–

• Electrons:– – Charge is 1.6 x 10-19C

© 2006 Mark S. Davis

Atomic Numbers

• Tell you:– Number of – Number of

© 2006 Mark S. Davis

© 2006 Mark S. Davis

Atomic Weights

• Atomic mass units (amu)

• 1 amu = 1.66054 x 10-24 g

• 1 g = 6.022137 x 1023 amu

• Mass on the table– 1 C = 12 amu

© 2006 Mark S. Davis

Average Mass

• Isotopes

• Ave mass = (mass x %) + (mass x %)

• C has two isotopes– C-12 at 98.93%– C-13 at 1.07 %– Determine the average atomic mass

© 2006 Mark S. Davis

The Periodic Table

• Family/Group–

• Period–

• Isotopes

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Types of elements

• Alkali Metals

• Alkaline Earth Metals

• Transition Metals

• Metalloids

• Non-metals

• Noble Gases

• Halogens

• Chalcogens

• Pnictides

• F-block

• Transuranium

© 2006 Mark S. Davis

Molecules and Ions

• Molecule:– Chemically combined elements

•

• Diatomic Molecule

•

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Formulas

• Molecular–

• Empirical–

• Structural–

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IONS

• Cation:–

• Anion:–

• Polyatomic:–

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Predicting Charges

• Based on the Periodic Table• Na• Br• O• Ca• Al• Si

© 2006 Mark S. Davis

Ionic Compounds

• Contain cations and anions–

• Use ELECTRONEGATIVITY to determine whether a compound is ionic–

© 2006 Mark S. Davis

Ionic Compounds

• Most ionic compounds can only be represented by empirical formulas–

• Writing formulas for ionic compounds– – –

© 2006 Mark S. Davis

Nomenclature

• System to ‘easily’ name chemical compounds.

• Organic, rules, rules, rules… – Ethane, ethanol, dimethyl ether

• Inorganic – much simpler

© 2006 Mark S. Davis

Ionic Naming

• Look at Periodic Table… Oxidation number

• Cations with one possible charge keep name– – – –

© 2006 Mark S. Davis

Ionic Naming

• Look at Periodic Table… Oxidation number

• Cations with more than one possible charge– – –

• Use the Stock System

© 2006 Mark S. Davis

Stock System

• Use a Roman Number, I, II, III, IV, V, VI to represent the oxidation number

•

• Cr+3

• Copper (I)

© 2006 Mark S. Davis

Anions

• Monatomic:–Ending is changed to

• Polyatomic: some have –ide ending–CN-

–OH-

© 2006 Mark S. Davis

Practice

• Write the formula for the following:–

–

© 2006 Mark S. Davis

Oxyanions

• Oddly enough… contain oxygen!–Ending is changed to:

• -ate • -ite

• Chlorine series

© 2006 Mark S. Davis

Practice

• Name the following–

–

–

© 2006 Mark S. Davis

Acids• Defined:

– Donate a proton

• Anion needs to be balance by hydrogen

• KNOW THE SIX STRONG ACIDS

© 2006 Mark S. Davis

Binary MOLECULAR Compounds

• Characterized by covalent bonds, not ionic

• Use prefixes mono-, di-, tri-, etc…

• More positive element named first

• Second element has –ide ending

© 2006 Mark S. Davis

Practice

• Name the following– – –