The intensity of the flame colour of alkali metals can be measured using

The colour of Lithium ion in Burner flame

The green coating on copper status when exposed to atmosphere for a long time in due to the formation of

A grey- green gelatinous precipitate formed when iron salts is treated with alkali

The most abundant metal in the Earth crust

The gas liberated when zinc in treated with dilute acid or steam

The presence of copper ions in compounds can be detected using