Ozone is a special kind of oxygen made up of three oxygen atoms, so its chemical formula is O₃. It is different from the oxygen we breathe, which has two atoms and is called O₂. Ozone is very important because it forms a layer high up in the sky called the ozone layer. This layer protects all living things by stopping the sun’s harmful ultraviolet (UV) rays from reaching the Earth. Without this layer, many plants, animals, and people could get sick from too much sun exposure. Ozone is also used in some cleaning and water-purifying processes because it can kill germs. However, ozone near the ground can be harmful and cause breathing problems. So, ozone is both helpful and sometimes dangerous depending on where it is found. Remember, O₃ means three oxygen atoms joined together, and this is why ozone has its special properties.