States of Matter and Intermolecular Forces
How Molecules Move
Three Common States
In solids, particles are tightly packed and mostly vibrate in place. In liquids, particles stay close but move around. In gases, particles are far apart and move freely.
States of Matter
Solid
- Fixed shape
- Fixed volume
- Strong particle attractions
Liquid
- No fixed shape
- Fixed volume
- Moderate attractions
Intermolecular Forces
Intermolecular forces are attractions between molecules. They are weaker than chemical bonds, but they still strongly affect melting point, boiling point, and viscosity.
Temperature and Motion
When temperature rises, particles usually move faster because they have more kinetic energy.
Which state of matter has particles farthest apart?
In gases, particles are much farther apart than in solids or liquids.
Correct answer: Gas
What do we call attractions between molecules?
These are forces acting between separate molecules.
Correct answer: intermolecular forces
Which state has a fixed volume but no fixed shape?
Liquids keep volume but take the shape of their container.
Correct answer: Liquid
From Forces to Properties
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1
Identify how strongly molecules attract each other.
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2
Consider how freely particles can move.
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3
Predict whether the material is solid, liquid, or gas.
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4
Relate the motion to observable properties.
What usually happens to particle motion when temperature increases?
Higher temperature generally means faster particle motion.
Correct answer: it increases