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 molecular
structure of substance is not altered.
E.g. colour, odour, melting point, density
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• Chemical Properties: any characteristic of a substance that
involves ability (or inability) of substance to react to form other
substances. The molecular structure of substance being
studied (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 amount
of substance present. They depend on the internal makeup of
the substance.
E.g. density, boiling point of a pure substance
• Extensive Properties: characteristics depending on amount of
substance present.
E.g. mass, volume, heat content
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Homogeneous: a substance composed of one phase and
uniform in composition and properties throughout
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Heterogeneous: a substance containing two or more distinct
phases. Composition and physical properties vary from one part
of mixture to another.
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Physical Changes: process whereby a substance changes in
physical appearance without changing basic identity (molecular
structure is preserved).
E.g. all changes of state
liquid
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gas
6
• Chemical Changes: or chemical reactions involve
transformation of substances into chemically different
substances by rearrangement of atoms. Chemical change
occurs when there is “change in composition”.
reactants
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products
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Classification of Matter:
o matter is made up of elements found on periodic table
o molecules of matter, like Lego bricks, can be pulled apart
into atoms and rearranged into completely different
molecules.
Some commonly used terms are:
• Atom: smallest particles or building blocks of matter
• Molecule: particle formed by the chemical combination of two
or more atoms
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• Mixture: made up of two or more substances each with its
own 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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• Element: a pure substance made of one type of atom. Cannot
be separated into simpler substances.
or
• Compound: a pure substance made up of two or more
elements hooked together so that all molecules are identical
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Matter
Heterogeneous
Mixture
Several Phases
Homogeneous
Mixtures or
Solutions
Physical
Separation
Physical
Separation
Compounds
Homogeneous
Matter
One Phase
Pure
Substances
or
Elements
Chemical
Separation
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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
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