Final answer:
A spectroscope is used to analyze the light spectrum emitted by a heated gas, which contains unique patterns for each element, allowing identification of unknown gases.
Step-by-step explanation:
A spectroscope is an instrument used to separate and analyze the light emitted by a substance. When a gas is heated, it emits light at specific wavelengths characteristic of the elements within it. By using a spectroscope, the emitted light can be split into its component colors, or spectrum. The unique pattern of lines in this spectrum can be compared to known spectra to identify the elements present in the unknown gas. This is based on the principle that each element has a unique atomic emission spectrum due to its electrons emitting different wavelengths of light when returning to their ground state. Thus, spectroscopy is invaluable in fields like chemistry, astronomy, forensics, and environmental science for substance identification.