Thermal Properties of Matter Topic

Thermometry

Concept 3 demos

Open case of A.W. Faber Thermochrom crayons with multiple colored sticks labeled with temperatures in Celsius and a reference chart in the lid

Heat Sensitive Crayons

Thermochromic crayon marks on an aluminum plate change color at specific temperatures when heated with a propane torch. Students see that any reproducible temperature-dependent property can serve as a thermometer, …

Six liquid crystal sheets on a white surface with a reusable heat pad in center; one sheet shows teal/green activation, two show partial blue activation near the heat pad, others are black; orange identification stickers on corners

Temperature-Sensitive Liquid Crystals

Encapsulated liquid crystal sheets change color continuously across a calibrated temperature range, progressing from black through red, green, and blue. Students observe temperature-dependent physical properties and can visualize heat transfer …

Gas thermometer with copper spherical bulb, brass stem, Winsco gauge reading -60 to 60 cm Hg, brass valve with hose barb, and black handle

Finding Absolute Zero

Measure gas pressure at four known temperatures and plot pressure vs. temperature to experimentally determine absolute zero by linear extrapolation. Provides a concrete foundation for the Kelvin scale and Gay-Lussac's …

Liquid Expansion

Concept 4 demos

Glass bulb air thermometer mounted vertically on ring stand with two finger clamps, stem extending into a glass of pink-tinted water

Air Thermometer

Demonstrates Charles's Law by showing gas volume changes with temperature at constant pressure. Warming the bulb with your hands expands the trapped air, pushing water down the stem; cooling with …

Maximum density of water apparatus on an overhead projector in a lecture hall, with a cylindrical cooling jacket to the left and two projection thermometer readings visible on the screen above

Maximum Density of Water

Water reaches maximum density at ~4°C. When cooled from outside, the bottom thermometer reads higher than the top — the densest (4°C) water sinks while colder, less-dense water stays on …

Balance beam on a vertical stand with black base, two large silver cylindrical cans of equal size hanging from each end

Hot Air Balance

Demonstrates that equal volumes of warm and cold air have different masses. Heating one of two balanced cans causes the warm air inside to expand and partially escape, reducing its …

Solid Expansion

Concept 9 demos

Straight bimetallic strip with black wooden handle on a gray surface

Bimetallic Strip

Demonstrates differential thermal expansion: two metals bonded together expand at different rates when heated, causing the strip to bend dramatically (~90°). Connects directly to thermostats, circuit breakers, and bimetallic thermometers.

Thermostat demonstration on wooden base with two incandescent bulbs in black sockets, a bimetallic strip on a copper mounting bar above, and colored banana jack binding posts in center

Thermostat

Demonstrates how differential thermal expansion of a bimetallic strip creates mechanical switching in a thermostat circuit. Heating the strip causes it to bend, switching which of two indicator bulbs is …

Handheld ring-and-ball apparatus: two brass balls on rods with black handles and a brass ring on a wooden handle (Gravesande's ring and ball)

Ring and Ball

A brass ball that just fits through a brass ring no longer passes through when the ball is heated, but does pass when the ring is also heated. Directly addresses …

Properties of Materials at Low Temperatures

Concept 1 demo

Small lead bell with yellow wooden striker handle, next to a clear cylindrical Pyrex dish for liquid nitrogen

Lead Bell

A lead bell rings with a dull thud at room temperature but produces a clear, higher-pitched tone after cooling in liquid nitrogen. Students hear directly how Young's modulus and internal …