Page 40 - Canadian BC Science 9
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Describing Matter
Think of a simple substance you have used recently—maybe sugar or salt or water. What colour was it, or was it colourless? What was its melting point or boiling point? When you answer questions like these, you are describing properties of matter. Physical properties are characteristics of matter that can be observed or measured. Qualitative properties are properties that can be described but not measured. Quantitative properties are characteristics that can be measured numerically. Table 1.1 lists the common physical properties used to describe matter.
Suggested Activity
Conduct an Investigation 1-2C on page 24
Table 1.1 Physical Properties Description
Solid, liquid, gas
Colour
Ability to be beaten into sheets Ability to be drawn into wires
Shape or appearance of crystals Tendency to be attracted to a magnet
Ability to dissolve in water
Ability to conduct electricity or heat Resistance to flow
Ratio of a material’s mass to its volume Temperature of melting/freezing Temperature of boiling/condensing
The usefulness of a substance depends on which properties it has—and sometimes which properties it does not have. Common window glass, for example, does not form crystals and is not a good conductor of heat or electricity. But these “lacks” make it valuable. Because it is not crystalline, it can be easily bent and shaped when heated. It can be made into works of art, huge glass sheets called panes, and thousands of other glass products. Because it does not conduct heat or electricity well, it can be used for insulation. Figure 1.11 shows three results of glass’s properties: a decorative glass object, double-paned windows, and insulators for power lines.
Physical Property
Qualitative
State Colour Malleability Ductility Crystallinity Magnetism
Quantitative
Solubility
Conductivity
Viscosity
Density
Melting/freezing point Boiling/condensing point
Figure 1.11 Works of art, windows, and electrical systems take advantage of the physical properties of glass.
22 MHR • Unit 1
Atoms, Elements, and Compounds
