Nitrogen is classified as an element. It is represented by the symbol ‘N’ on the periodic table and has an atomic number of 7. As a pure substance, nitrogen cannot be broken down into simpler substances by chemical means, which is a key characteristic of elements.
In its natural state, nitrogen exists as a diatomic molecule, meaning it is commonly found as N2, where two nitrogen atoms are covalently bonded together. This form of nitrogen is abundant in the Earth’s atmosphere, making up about 78% of it. While nitrogen can form compounds with other elements—such as ammonia (NH3) or nitric acid (HNO3)—these are not representative of elemental nitrogen itself. Instead, they showcase nitrogen’s ability to bond and interact with other elements.
Unlike mixtures, which consist of two or more substances combined physically but not chemically, nitrogen as an element maintains its distinct chemical properties. Hence, when we refer to nitrogen in a chemical context, we are talking about an element: a basic building block of matter that cannot be subdivided into simpler substances through ordinary chemical processes.