Determine the magnitude of the vector going from (2, 1, 3) to (1, 1, 1).

\(\begin{array}{|rcll|} \hline &=& \sqrt{(2-1)^2+(1-1)^2+(3-1)^2} \\ &=& \sqrt{1+0+4} \\ &=& \sqrt{5} \\ \hline \end{array}\)