Ch 12. Learning Objectives The Physical States of Matter

Viscosity
•Some liquids flow more easily
than others.
•The resistance of a liquid’s flow
is called viscosity.
•The stronger the attractive
forces between the molecules, the
more viscous the liquid is.
•Some liquids are more viscous
because their molecules are long
and get tangled in each other,
causing them to resist flowing
Effect of the Strength of Intermolecular
Attractions on Properties
• The stronger the intermolecular attractions are, the
more energy it takes to separate the molecules.
• Substances with strong intermolecular attractions have
higher boiling points, melting points, and heat of
vaporization; they also have lower vapor pressures.
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