This document provides information about air and its properties. It discusses that air is a mixture of gases including nitrogen, oxygen, carbon dioxide and water vapor. It notes that air is present all around us but cannot be seen. The document outlines several properties of air such as being colorless, transparent, and lacking smell or taste. It then discusses various uses of air including for breathing, burning, filling balloons and tires, and helping birds and kites fly. The document also describes how different organisms inhale and exhale air and notes that air pollution occurs when gases, dust or smoke make the air unclean and unsafe. It lists some ways to reduce pollution and effects of air pollution on health.