## Heat Conductivity

Authors: Krista Botton and Jessica McLemore
Demonstration Equipment - Teacher's Guide
SED 695B
 Principles illustrated: Compares the heat (thermal) conductivity of 5 different metals: aluminum, brass, copper, nickel and steel. Standards addressed: Eighth Grade Science Standard Periodic Table 7c Students know substances can be classified by their properties, including their melting temperature, density, hardness, and thermal and electrical conductivity.
 Materials Explanation of principles involved Bunsen Burner Striker or matches Heat Conductometer Wax Each of the 5 metals extends from a central hub that is heated. Wax placed in a well on each labeled rod melts as the hub is heated. Metals with higher conductivity cause the wax to melt more quickly than those with lower conductivity. Procedure: Introduce lab and have students go to lab tables. Load wax into the conductometer and light Bunsen burners. Hold the thermal conductometer over the Bunsen burner with the central hub directly over the heat source. Observe the wax and record the order of the rods on which the wax melts. (Rods are labeled) Variations: Have the students time how long it takes to melt the wax on each metal. Have the students predict the order of melting and analyze if their predictions are correct. Depending on their prior knowledge or the amount of information previously presented in class about metals and/or periodic table properties and structure, students may be able to discuss why. Applications to Real Life: Cookwear design: Copper bottom pots with steel sides so that the contents heat quickly through the copper bottom with a high heat conductivity and stay warm through the steel sides that have a low heat conductivity. Electrical conductivity: relates well to electrical conductivity of each of the metals. Example: copper wiring. References & Links: