Ozone (O₃) is a compound, not an element. It is composed of three oxygen atoms chemically bonded together. Each oxygen atom in the ozone molecule is connected to the other two atoms through covalent bonds. Ozone is a pale blue gas with a distinct odor and is most commonly known for its presence in the Earth's stratosphere, where it forms the ozone layer. However, ozone can also be created and found at ground level through various processes, such as reactions involving pollutants and sunlight.