What is the primary purpose of spectroscopy in chemistry?

The primary purpose of spectroscopy in chemistry is to determine the properties of matter based on light interaction. This technique involves the study of how matter interacts with electromagnetic radiation across various wavelengths. By analyzing the light that is absorbed, emitted, or scattered by substances, chemists can gather information about the molecular structure, concentration, and specific characteristics of compounds and elements.

Spectroscopy serves as an essential tool for identifying substances and studying their properties, as different compounds respond uniquely to light, producing distinctive spectra. This can provide insights into molecular vibrations, electronic transitions, and other attributes critical for characterizing materials in a variety of fields, including organic chemistry, biochemistry, and analytical chemistry.

While measuring chemical reaction rates, synthesizing new compounds, or analyzing physical states of substances are all important aspects of chemistry, they do not capture the core function of spectroscopy as directly as understanding light-matter interactions does. Thus, option B accurately reflects the fundamental role of spectroscopy in the field.