I. All elements emit and absorb characteristic spectra. II. Spectral analysis is an important method of identifying environmental pollutants. III. The chemi...

Answer Details

The correct answer is (A) I, II, and III. I. All elements emit and absorb characteristic spectra: This is a fundamental principle of spectroscopy. When atoms or molecules absorb or emit light, they do so at specific wavelengths that are unique to that particular element or compound. This allows scientists to identify the chemical composition of a sample. II. Spectral analysis is an important method of identifying environmental pollutants: Spectral analysis is widely used to identify pollutants in the environment. By analyzing the absorption or emission spectra of a sample, scientists can determine what compounds are present and in what concentrations. III. The chemical composition of stars could be determined using spectral analysis: Astronomers use spectral analysis to study the chemical composition of stars. When light from a star passes through a prism or diffraction grating, it is separated into its component wavelengths, creating a spectrum. By analyzing the spectrum, astronomers can determine what elements are present in the star. Therefore, all the statements are correct, and the correct answer is (A) I, II, and III.