In chemistry an physics, the atomic nummer (cried the proton nummer an aa) is the number o protons foond in the nucleus o an atom an tharefore identical tae the charge nummer o the nucleus. It is conventionally representit bi the seembol Z. The atomic nummer uniquely identifies a chemical element. In an atom o neutral charge, the atomic nummer is equal tae the nummer o electrons.

Nummer theory (or arithmetic) is a branch o pure mathematics devoted primarily tae the study o the integers, sometimes cried "The Queen o Mathematics" acause o its foondational place in the discipline. Nummer theorists study prime nummers as well as the properties o objects made oot o integers (e.g., rational nummers) or defined as generalizations o the integers (e.g., algebraic integers). Notes Further readin G.H. Hardy; E.M. Wright (2008) [1938]. An introduction to the theory of numbers. Oxford University Press. ISBN 978-0-19-921986-5. Vinogradov, I.M. (2003) [1954]. Elements of Number Theory (reprint o 1954 ed.). Mineola, NY: Dover Publications. Ivan M. Niven; Herbert S. Zuckerman; Hugh L. Montgomery (2008) [1960]. An introduction to the theory of numbers (reprint of the 5th edition 1991 ed.). John Wiley & Sons. ISBN 978-81-265-1811-1. Kenneth H. Rosen (2010). Elementary Number Theory (6th ed.). Pearson Education. ISBN 978-0-321-71775-7. Borevich, A. I.; Shafarevich, Igor R. (1966). Number theory. Pure and Applied Mathematics. 20. Boston...