Bohr's model of atomic structure based on spectral emissions

Question

Why are flames different colors when a different element is added?  What do different colors mean?

 

Answer 1

When the atoms of a gas or vapor are excited, for instance by heating or by applying an electrical field, their electrons are able to move from their ground state to higher energy levels. As they return to their ground state, they emit photons of very specific energy. This energy corresponds to particular wavelengths of light, unique to each element and so produces particular colors of light.