State of Matter Chemistry Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

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.

Solution

  1. 1
    In the particle model, solids have particles locked in fixed positions in a crystalline or amorphous lattice; liquids have particles that slide freely past one another.
  2. 2
    Glass is an amorphous solid — its particles are fixed but not in a regular crystal pattern. It does not flow at room temperature.
  3. 3
    Old windows are thicker at the bottom because of manufacturing imperfections in early glass-making (crown glass process), not because the glass flowed over time.

Answer

Glass is an amorphous solid, not a slow liquid. Thickness variation is a manufacturing artifact.\text{Glass is an amorphous solid, not a slow liquid. Thickness variation is a manufacturing artifact.}
This is a famous misconception. Amorphous solids like glass lack long-range crystal order but still have fixed particle positions. The timescale for glass to flow at room temperature exceeds the age of the universe.

About State of Matter

The distinct physical forms that matter can take depending on the arrangement, spacing, and motion of its particles.

Learn more about State of Matter →

More State of Matter Examples

Example 1 easy

Compare the three common states of matter (solid, liquid, gas) in terms of particle arrangement, sha

Example 2 medium

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

Example 3 easy

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

← All State of Matter Examples State of Matter Concept