Colors of Elements in a Flame - Sodium Chloride
Sodium chloride imparts a bright yellow-orange color to a flame.
descriptive chemistry
Colors of Elements in a Flame - Strontium Chloride
Strontium chloride imparts a bright red color to a flame.
Colors of Elements in a Flame - Animation of Photon Emission
Photon emission is illustrated using an animation.
Copper penny with concentrated nitric acid
The reaction of a copper penny (minted pre-1982) and concentrated nitric acid (15 M) is shown. Red-brown nitrogen dioxide is generated and some of the copper dissolves to form a blue solution of copper(II) nitrate.
Oxidation and reduction of copper
A piece of copper metal is heated in a flame and oxidized to black copper oxide by air. The oxidized copper is reduced when placed in a hydrogen atmosphere. When removed from the hydrogen atmosphere, the metal is again oxidized.