Atomic characteristics refer to the unique properties of atoms that define their behavior and interactions. These include atomic number, which indicates the number of protons in an atom's nucleus, and atomic mass, the total number of protons and neutrons. The arrangement of electrons in different energy levels also plays a crucial role in determining how atoms bond with each other. Another important aspect of atomic characteristics is electronegativity, which measures an atom's ability to attract electrons in a chemical bond. Additionally, the concept of isotopes highlights that atoms of the same element can have different numbers of neutrons, leading to variations in atomic mass. Understanding these characteristics is essential in fields like chemistry and physics.