what does atomic number represent

1 month ago 11
Nature

The atomic number of an element represents the number of protons in the nucleus of each atom of that element. It uniquely identifies the element because every atom of a given element has the same number of protons

. In a neutral (non-ionized) atom, the atomic number also equals the number of electrons orbiting the nucleus, balancing the positive charge of the protons with an equal negative charge from the electrons

. Thus, the atomic number:

  • Defines the chemical identity of an element (e.g., atomic number 8 means oxygen)
  • Equals the number of protons in the nucleus
  • Equals the number of electrons in a neutral atom

The atomic number is symbolized by ZZZ and is used to arrange elements in the periodic table in order of increasing ZZZ

. In summary, the atomic number represents the number of protons in an atom's nucleus and determines the element's identity and its position in the periodic table.