∞ generated and posted on 2022.01.25 ∞

Entity consisting of protons and neutrons found in a compact nucleus while associated electrons exist in an extra-nuclear probabilistic cloud.

Atoms in their various forms (e.g., including ions), and their interactions, form the basis of chemistry.

In a neutral atom the number of protons (positively charged) equals the number of electrons (negatively charged). When electron numbers are greater or less than this, in whole numbers (i.e., -1, +2, -2, etc.), then the atom is said instead to be an ion. When the number of protons found in an atom differ then the so differing atoms are said to be different elements. When the number of neutrons differ then the atoms are said to be different isotopes.

Atoms are the basic unit of chemistry, which is the study especially of interactions between atoms. That interaction involves especially interactions between the electrons associated with atoms.

Atoms also different in terms of the mass (atomic mass), their size, and their propensity to gain or lose electrons (electronegativity). In addition, and greatly impacting their chemistry, different types of atoms can posses different numbers of valence electrons.