What is a pure substance?
Non-characteristic properties
Characteristic properties (physical and chemical)
Determining an unknown substance
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Substance made up of 1 type of atom OR 1 type of
molecule
Mixtures are NOT pure substance
2 types
◦ Elements
 1 type of atom
 Iron, oxygen,
◦ Compounds
 At least 2 types of atoms
 Water, salt,
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A property that is shared by many substances
It does not allow you to identify it
Examples: mass, volume, temperature, color,
shape.
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A property that is unique to that one substance
Allows you to identify it right away
Examples: DNA, boiling point, density
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Once the observation of the property is made, the
molecular make-up of the substance remains the
same
Examples: melting point, boiling point, density,
solubility
See Table 1.30 on page 23
of textbook
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Once the action or observation is made, the
substance is no longer the same, its molecular
make-up has changed
Examples: burning, digesting, use of indicators
See Table 1.31 on page 24 of textbook
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There are many tests that can be done to identify a
substance which include:
◦ Conductivity: if light of conductivity meter comes on
◦ Malleability: ability to bend
◦ Magnetism: substance is attracted or repelled by a
magnet
◦ Smell
◦ Colour
◦ Metallic luster: shine, all metals shine
◦ Density
◦ See tables on pages 23 and 24 of textbook