What color is nitrogen dioxide typically observed to be?

Nitrogen dioxide is typically observed to be reddish brown in color. This reddish brown hue is due to the absorption of light at certain wavelengths, which is a characteristic feature of this gas. In atmospheric conditions, nitrogen dioxide can contribute to the brownish coloration of smog. Understanding the distinct color of nitrogen dioxide is important, particularly in environmental science and pollution studies, as it helps in identifying the presence of this gas in the atmosphere and assessing air quality.

While other gases may be colorless or exhibit different colors, nitrogen dioxide is specifically recognized for its reddish brown appearance, which is a crucial identifying factor in various chemical and environmental applications.