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\begin{document}

%-------------------------------------------------------------------


\section*{atomic number}

\hypertarget{context}{}\subsubsection*{{Context}}\label{context}

\hypertarget{physics}{}\paragraph*{{Physics}}\label{physics}

[[!include physicscontents]]

\hypertarget{contents}{}\section*{{Contents}}\label{contents}

\noindent\hyperlink{idea}{Idea}\dotfill \pageref*{idea} \linebreak
\noindent\hyperlink{references}{References}\dotfill \pageref*{references} \linebreak


\hypertarget{idea}{}\subsection*{{Idea}}\label{idea}

The \emph{atomic number} of a [[chemical element]] is the [[natural number|number]] of [[protons]] in any [[atomic nuclei]] of this element.

For instance [[carbon]] has atomic number 6.

The [[periodic table of chemical elements]] organizes them by their atomic number, together with other properties.

The corresponding [[natural number|number]] of [[neutrons]] on the nucleus tends to be close to the number of protons, hence to the atomic number of the element, but need not equal it and my differ considerably for heavy elements. These variants of neutron number for given atomic number specify the \emph{[[isotopes]]} of the [[chemical element]].

\hypertarget{references}{}\subsection*{{References}}\label{references}

See also

\begin{itemize}%
\item Wikipedia, \emph{\href{https://en.wikipedia.org/wiki/Atomic_number}{Atomic number}}

\end{itemize}
Speculative analogy to [[characteristic classes]] of [[complex surfaces]] (different from but inspired by [[Skyrmion]] [[model (in theoretical physics)|models]] for [[atomic nuclei]]):

\begin{itemize}%
\item [[Michael Atiyah]], [[Nicholas Manton]], \emph{Complex Geometry of Nuclei and Atoms} (\href{https://arxiv.org/abs/1609.02816}{arXiv:1609.02816})

\end{itemize}
[[!redirects atomic numbers]]



\end{document}