Element 8 is oxygen, which has an atomic number of 8. It is a non-metallic element that is essential for life, as it is a key component of water and many organic molecules. Oxygen is the third-most abundant element in the universe, after hydrogen and helium. In its natural form, oxygen is a gas that makes up about 21% of the Earth's atmosphere. It is also found in the Earth's crust, in the form of oxides such as silicon dioxide and aluminum oxide. Oxygen is highly reactive and can form compounds with almost all other elements, making it an important element in many chemical reactions.