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Lecture 1-01: Chemistry Basics Matter : anything that occupies space and has mass, anything

made up of atoms

Is air a form of matter? How do you know? Physical Properties : characteristics observed without changing

basic identity of substance. The key is that molecularstructure of substance is not altered.E.g. colour, odour, melting point, density

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Chemical Properties : any characteristic of a substance thatinvolves ability (or inability) of substance to react to form othersubstances. The molecular structure of substance beingstudied (reactant) is altered if reaction occurs.

e.g. flammability of carbon in oxygen gas e.g. non reactivity of Au in hydrochloric acid solution

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Intensive Properties : characteristic not depending on amountof substance present. They depend on the internal makeup ofthe substance.E.g. density, boiling point of a pure substance

Extensive Properties : characteristics depending on amount ofsubstance present.E.g. mass, volume, heat content

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Homogeneous : a substance composed of one phase anduniform in composition and properties throughout

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Physical Changes : process whereby a substance changes inphysical appearance without changing basic identity (molecularstructure is preserved).

E.g. all changes of state

liquid gas

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APSC 131 Introduction Lecture 1-01 Basic Concepts 7

Chemical Changes : or chemical reactions involvetransformation of substances into chemically differentsubstances by rearrangement of atoms. Chemical changeoccurs when there is change in composition .

reactants products

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APSC 131 Introduction Lecture 1-01 Basic Concepts 8

Classification of Matter :o matter is made up of elements found on periodic tableo molecules of matter, like Lego bricks, can be pulled apart

into atoms and rearranged into completely differentmolecules.

Some commonly used terms are:

Atom : smallest particles or building blocks of matter

Molecule : particle formed by the chemical combination of twoor more atoms

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Mixture : made up of two or more substances each with itsown chemical identity. Homogeneous mixtures are solutions .

Pure substance : made up of one type of molecule and always homogeneous . May be an element or a compound .

or

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APSC 131 Introduction Lecture 1-01 Basic Concepts 10

Element : a pure substance made of one type of atom . Cannotbe separated into simpler substances.

or

Compound : a pure substance made up of two or moreelements hooked together so that all molecules are identical

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APSC 131 Introduction Lecture 1-01 Basic Concepts 11

Matter

Heterogeneous Mixture

Several Phases

Homogeneous Matter

One PhasePhysicalSeparation

Homogeneous Mixtures or

Solutions

PureSubstances

or PhysicalSeparation

Compounds Elements

ChemicalSeparation

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Suggested homework Read Petrucci pages 1- 8 Carefully read through lecture 1-02 on naming chemical

compounds and try to answer any of the questions asked. Problems Chapter 1: 1, 5, 7, 9, 11, 13 and 15