State of Matter Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of State of Matter.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

The form matter takes depending on the arrangement and movement of its particles: solid, liquid, or gas (plus plasma).

Particles packed tight and vibrating = solid. Particles sliding past each other = liquid. Particles flying freely = gas.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: The state of matter depends on the balance between particle energy (temperature) and attractive forces between particles.

Common stuck point: Gas particles are not 'nothing' — they have mass and exert pressure. Gas is still matter.

Worked Examples

Example 1

easy
Compare the three common states of matter (solid, liquid, gas) in terms of particle arrangement, shape, and volume.

Solution

  1. 1
    Solid: particles tightly packed in fixed positions. Definite shape and definite volume.
  2. 2
    Liquid: particles close together but can slide past each other. Indefinite shape but definite volume.
  3. 3
    Gas: particles far apart with rapid random motion. Indefinite shape and indefinite volume.

Answer

\text{Solid: fixed shape/volume. Liquid: fixed volume. Gas: neither fixed.}
The state of matter depends on the balance between kinetic energy (motion) and intermolecular forces (attraction). Increasing temperature provides more kinetic energy, favoring less ordered states.

Example 2

medium
Why can gases be compressed easily while liquids and solids cannot?

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
At room temperature, classify each as solid, liquid, or gas: (a) mercury, (b) oxygen, (c) table salt.

Example 2

hard
Glass appears solid but some claim it is actually a very slow-moving liquid because old windows are thicker at the bottom. Evaluate this claim using the particle model of solids and liquids.
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Background Knowledge

These ideas may be useful before you work through the harder examples.

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