Elements and the periodic table > decomposition

This experiment involves a comparison between the thermal stabilities of carbonates of reactive metals, such as sodium and potassium, and the carbonates of less reactive metals, such as lead and copper.
 

In this demonstration experiment, a small conical heap of orange ammonium dichromate(VI) is ignited and starts to decompose exothermically. The reaction resembles a volcanic eruption, producing sparks, a large volume of green chromium(lll) oxide 'ash', steam and nitrogen gas.