The atomic number of an element refers to the number of protons found in the nucleus of an atom of that element. It is a fundamental property of an element that distinguishes it from other elements.
The atomic number is represented by the symbol "Z" and is typically listed above or to the left of the element's symbol in the periodic table. In a neutral atom, the atomic number also corresponds to the number of electrons orbiting the nucleus.
Each element has a unique atomic number. For example, hydrogen (H) has an atomic number of 1, indicating it has one proton in its nucleus. Oxygen (O) has an atomic number of 8, indicating it has eight protons in its nucleus.
The atomic number determines an element's position in the periodic table and is used to identify and classify elements. Elements are arranged in increasing order of atomic number in the periodic table, which helps to organize and predict their chemical properties and behavior.