Chapter 28, Problem 42A

To determine

To explain: The cause of beautiful colors appearance while burning the materials in a fireplace. 

Explanation of Solution

Introduction: 

When atoms are heated in the material, the electrons are excited to higher energy levels. Explanation: 

The atom in the materials has its own characteristic having a set of energy levels.  When the atom is heated, it changes its energy levels. The wavelength of light depends on the difference in energy levels. The materials are chemically composed. When they burn, they produce different spectral lines due to the mixing of different levels of energy and they produce different colors. Therefore, the metal gives its characteristic emission spectrum.

Conclusion:

Due to the change in the energy levels, the materials give beautiful colors when they are burnt.