What are the characteristic flame color for sodium, potassium, barium, copper, strontium, and calcium? Explain why?

Question

Ans: i know the flame colours, but for the explain why, could the below be a possible answer?

The characteristic flame color is due to the shift in the energy levels of the element, and when an element is in the high energy zone it is unstable and therefore to stabilize it self it gives of a quantized value of photon of light which corresponds to the color of the flame.

Answer 1

Your answer sounds like lawyer talk.

The colors represent specific energy transitions, which are characteristic of specific electron energy levels in each element. Each element has a characteristic outer electron orbital pattern (see the periodic table). So, the outer transitions to higher energy levels and back are fingerprints to specific elements.
So we see these colors, and we can identify the energy transition, and the element itself causing it.

Answer 2

The colours that we see for an element in a flame is a mixture of the colours of the lines from emission spectra.

Each line colour results from an electron 'falling' from a higher energy level to a lower energy level. Because the spacing of the energy levels is different for each element each element emits a different pattern of lines, the so called 'fingerprint' of lines.

Thus while when sodium (or its compounds) is placed in a flame we see an orange colour, this is made up of two orange lines, plus a green, red and blue lines.

see http://members.misty.com/don/spectra.html