Atomic Number

The atomic number is the number of protons found in the nucleus of an atom. It defines the identity of an element; for example, hydrogen has an atomic number of 1, while oxygen has an atomic number of 8. Each element's atomic number uniquely determines its position in the periodic table and its chemical properties. In a neutral atom, the atomic number also indicates the number of electrons surrounding the nucleus, balancing the positive charge of the protons with the negative charge of the electrons, leading to a stable structure.