% !Mode:: "TeX:UTF-8"
\documentclass[tikz]{standalone}
\usepackage{ifthen}
\usepackage{fontspec}
\usepackage{xcolor}
\usetikzlibrary{calc}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{decorations.pathmorphing}
\setmainfont[Mapping=tex-text,Numbers=OldStyle]{Liberation Sans}
\tikzset{
  blurred action/.style={
    line width=\pgflinewidth+.2pt,draw opacity=.1,draw=#1,
  },
  blurred recurs/.code 2 args={%
    \pgfmathtruncatemacro{\level}{#1-1}%
    \ifthenelse{\equal{\level}{0}}%
    {\tikzset{preaction={blurred action=#2}}}%
    {\tikzset{preaction={blurred action=#2,blurred recurs={\level}{#2}}}}
  },
  blurred/.style={preaction={blurred recurs={10}{#1}},draw opacity=1,draw=#1},
}
\begin{document}
	\begin{tikzpicture} [
			electron/.style={fill=orange,draw=brown},
			noyau/.style={fill=gray,draw=black},
			orbite/.style={very thick},
			titre/.style={font=\bfseries},
			fleche/.style={-Latex,ultra thick,draw=orange,fill=orange,shorten <=1.5mm,shorten >=1.5mm},
			legende/.style={font=\small},
			changement/.style={decorate,decoration={coil,aspect=0},draw=red,-Latex,very thick},
			flegende/.style={-Latex}
		]
		\foreach \x in {-4cm,4cm} {
			\path [noyau] (\x,0) circle [radius=0.3cm];
			\foreach \r/\col in {1cm/blue!30!white,2cm/blue!30!white,3cm/gray} {
				\path [orbite,blurred=\col] (\x,0) circle [radius=\r];
			}
			\path [electron,xshift=\x] (60:1cm) circle [radius=0.1cm];
			\path [electron,xshift=\x] (60:3cm) circle [radius=0.1cm];
			\path [electron,xshift=\x] (230:2cm) circle [radius=0.1cm];
		}
		\node [titre] at (-4,4) {Absorption};
		\node [titre] at (4,4) {Émission};
		\path [fleche,xshift=-4cm] (60:1cm) -- (60:3cm);
		\path [fleche,xshift=4cm] (60:3cm) -- (60:1cm);
		\node (noya) at (-7,2) [legende,left] {Noyau};  
		\draw [flegende] (noya) -- ($ (-4,0)+(140:0.1cm) $);
		\node (noyb) at (7,-3) [legende,right] {Noyau};  
		\draw [flegende] (noyb) -- ($ (4,0)+(-50:0.3cm) $);
		\node (excite) at (0,3) [legende] {État excité};
		\draw [flegende] (excite) -- ($ (-4,0)+(50:3cm) $);
		\draw [flegende] (excite) -- ($ (4,0)+(130:3cm) $);
		\node (fondamental) at (0,-3) [legende,text width=3cm,align=center] {Niveau d'énergie fondamental};
		\draw [flegende] (fondamental) -- ($ (-4,0)+(-50:1cm) $);
		\draw [flegende] (fondamental) -- ($ (4,0)+(-130:1cm) $);
		\path [changement] (-4.5,3.5) -- ($ (-4,0)+(60:1cm)+(130:2mm) $);
		\path [changement] ($ (4,0)+(60:1cm)+(130:2mm) $) -- (3.5,3.5);
		\node (absorption) at (-5,3.2) [legende,text width=4cm,left,align=flush right] {Absorption d'énergie par l'atome};
		\draw (absorption) -- (-4.7,3.3);
		\node (emission) at (5,3.2) [legende,text width=4cm,right,align=flush left] {Émission d'un quantum d'énergie};
		\draw (emission) -- (3.8,3.3);
	\end{tikzpicture}
\end{document}