Fix of one typo I introduced in my last commit on text changes.

Tests/Data/Parabolic/ComponentTransport/ReactiveTransport/DecayChain/DecayChain.ipynb

@@ -99,7 +99,7 @@
     "\\frac{\\partial \\left( \\phi c_{i} \\right)}{\\partial t} = \\nabla \\cdot \\left(\\phi \\mathrm{D_p} \\nabla c_{i} \\right) + \\phi k_{i-1} c_{i-1} - \\phi k_{i} c_{i}, \\quad \\forall i = 1,2,...,n,\n",
     "$$\n",
     "\n",
-    "where $c_{i}$ [mol/m$^3$] is the concentration of radionculide $i$, $\\phi$ [-] is the porosity, $\\mathrm{D_p}$ [m$^2$/s] is the pore diffusion coefficient, and $k_{i}$ [1/s] is the first-order decay constant of a radionuclide $i$, i.e.:\n",
+    "where $c_{i}$ [mol/m$^3$] is the concentration of radionuclide $i$, $\\phi$ [-] is the porosity, $\\mathrm{D_p}$ [m$^2$/s] is the pore diffusion coefficient, and $k_{i}$ [1/s] is the first-order decay constant of a radionuclide $i$, i.e.:\n",
     "\n",
     "$$\n",
     "k_i = \\mathrm{ln} 2 \\, / \\, t_{i,1/2},\n",