Topic 1.2a – States of Matter

In this topic we go over the 4 states of matter solids, liquids, gases, and plasmas. We review the properties of each of these states and what happens when they are heated or cooled. Take your video notes as you follow along, complete your interactive activity, and do excellent on your topic quiz!

Pretest Grade: 0 to 79 (Beginning & Developing)

Pretest Grade: 80 to 100 (Proficient & Distinguished)

FSI: States of Matter – Interactive Activity (Grade 8 GSE)

8th Grade Physical Science • Georgia Standards of Excellence (S8P1, S8P2)

States of Matter – Interactive Reading, Diagrams, Graphs & Practice

Explore particle motion and energy in solids, liquids, and gases, then practice with drag-and-drop, dropdowns, and Milestones-style questions.

Reading: Particle Motion & Properties

Solids have particles packed close together in fixed positions. They vibrate but do not flow, giving solids a definite shape and volume.

Liquids have particles that are close but can slide past each other. Liquids have a definite volume but take the shape of their container.

Gases have particles far apart and moving fast in all directions, filling any container. They have neither definite shape nor volume.

Heating increases average kinetic energy of particles. During a phase change, temperature stays constant while energy goes into changing particle spacing (potential energy).

Diagram: Particle Visualizer

Tap a state to see particle spacing and motion trend.

Graph: Heating Curve of Water

Temperature vs time • Phase change segments

Solid warming (T↑)

Melting (T const)

Liquid warming (T↑)

Boiling (T const)

Gas warming (T↑)

Drag each label to its correct segment on the heating curve.

Drag & Drop: Sort by State at Room Temperature (~25°C)

Aluminum can

Mercury

Oxygen

Milk

Granite rock

Carbon dioxide

Vegetable oil

Table salt (NaCl)

Solid

Definite shape & volume

Liquid

Takes container shape, definite volume

Gas

Fills container

Dropdown Quick Check

During melting, the temperature of a pure substance Gases have average kinetic energy compared to solids at the same temperature. Liquids have a but no definite shape.

Milestones-Style Practice (5 Questions)

1) Which explanation best describes why a gas fills its container?

A. Gas particles are tightly packed and cannot move. B. Gas particles are far apart with weak attraction and move rapidly in all directions. C. Gas particles vibrate in fixed positions. D. Gas particles slide past each other but remain close together.

2) Refer to the heating curve. What happens during segment B–C?

A. Temperature increases and particles move faster in the solid. B. Temperature decreases as the solid cools. C. Temperature stays constant while particles overcome attractions to change from solid to liquid. D. Temperature stays constant while liquid changes to gas.

3) Which is a physical change?

A. Iron rusting B. Wood burning C. Vinegar reacting with baking soda D. Water freezing into ice

4) As temperature increases, what happens to the average kinetic energy of particles?

A. It increases. B. It decreases. C. It remains constant. D. It becomes zero.

5) Which statement about liquids is correct?

A. No definite shape or volume. B. Definite shape and volume. C. No definite shape but definite volume. D. Definite shape but no definite volume.