Gold Puzzle

Gold is a chemical element with the symbol Au and atomic number 79. It is a dense, soft, malleable, and ductile metal with an attractive, bright yellow color and luster that is maintained without tarnishing in air or water. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements, solid under standard conditions. The metal therefore occurs often in free elemental (native) form, as nuggets or grains in rocks, in veins and in alluvial deposits. Less commonly, it occurs in minerals as gold compounds, such as with tellurium as calaverite, sylvanite and krennerite.