Chapter 3, Problem 3.53QP

Interpretation Introduction

Interpretation:

The ability of describing by astronomers that the elements present in distant stars by analyzing the electromagnetic radiation emitted by the stars should be explained using the concept of emission spectrum.

Concept Introduction:

The electrons are excited thermally when the light is used by an object.  As a result, an emission spectrum comes.  The emission spectrum of a substance is seen by energizing a sample of material with either thermal energy or some other form of energy (such as a high-voltage electrical discharge if the substance is a gas).  A “red-hot” or “white-hot” iron bar freshly removed from a fire produces a characteristic glow.  The glow is the visible portion of its emission spectrum.  The heat given off by the same iron bar is another portion of its emission spectrum called the infrared region.  A feature common to the emission spectrum of the sun and that of a heated solid is that both are continuous.  Hence, all wavelengths of visible light are present in each spectrum.