Is the flame coloration a test for the metal or for nitrate ion?

Metallic ion because the metallic ions will enter an exited state and release photons energy, in the form of light, as they return to their ground state.

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.