Procedure Put on the safety glasses or goggles. Stand the tea bag on the heat and fire resistant surface with its open end down. Use the lighter to light it at the top. The small amount of charred tea bag remaining can be disposed of in the trash. Air currents generated by heat are called convection currents.
Convection currents form because of the difference in density between hot and cold air.
In this demo, the convection current generated by heat from the burning tea bag creates an updraft. The updraft is what causes the bag to lift off the bench top. Featured products Patriotic Color Chemistry Kit Students cause colorless solutions containing phenolphthalein, calcium chloride, and thymolphthalein to turn red, white, blue, and then colorless again. The demonstration kit is for 3 demonstrations. The classroom kit is for 5 stations of 2 or 3 students and contains enough material for 2 or 3 classes.