\begin{table}%t2
%\centering
\par
\caption{Heavy element abundances. \label{tab3}}
\begin{tabular}{lcc} \hline \hline
Property       &Bright&Total \\ \hline
$T_{\rm e}$(O {\sc iii}), K           &$20~120\pm240$  &$20360\pm480$ \\
$T_{\rm e}$(O {\sc ii}), K            &$15~620\pm170$  &$15630\pm340$ \\
$T_{\rm e}$(S {\sc iii}), K          &$18~750\pm200$  &$18910\pm400$ \\
$N_{\rm e}$(O {\sc ii}), cm$^{-3}$    &$120\pm50$     &$150\pm80$    \\
$N_{\rm e}$(Ar {\sc iv}), cm$^{-3}$   &$6000\pm2000$   &    ...    \\
$N_{\rm e}$(S {\sc ii}), cm$^{-3}$    &$146\pm41$     &$213\pm74$    \\ \\
O$^+$/H$^+$, ($\times$10$^5$)   &$0.164\pm0.005$&$0.211\pm0.013$  \\
O$^{2+}$/H$^+$, ($\times$10$^5$)&$1.838\pm0.054$&$1.664\pm0.090$  \\
O$^{3+}$/H$^+$, ($\times$10$^5$)&$0.032\pm0.001$&$0.081\pm0.006$  \\
O/H, ($\times$10$^5$)           &$2.034\pm0.054$&$1.956\pm0.091$  \\
12+log O/H                      &$7.31\pm0.01$  &$7.29\pm0.02$ \\ \\
N$^+$/H$^+$, ($\times$10$^7$)   &$0.779\pm0.019$&0$.673\pm0.033$  \\
$ICF$(N)                        &     11.25     &      8.53     \\
N/H, ($\times$10$^7$)           &$8.765\pm0.235$&$5.741\pm0.304$  \\
log N/O                         &$-1.37\pm0.02$&--$1.53\pm0.03$ \\ \\
Ne$^{2+}$/H$^+$, ($\times$10$^6$)&$2.977\pm0.092$&$2.941\pm0.199$ \\
$ICF$(Ne)                        &      1.04     &      1.06     \\
Ne/H, ($\times$10$^6$)           &$3.099\pm0.102$&$3.126\pm0.234$  \\
log Ne/O                         &$- 0.82\pm0.02$&$-0.80\pm0.04$  \\ \\
S$^{+}$/H$^+$, ($\times$10$^7$) &$0.314\pm0.006$ &$0.348\pm0.013$ \\
S$^{2+}$/H$^+$, ($\times$10$^7$)&$1.539\pm0.052$ &$1.433\pm0.136$ \\
$ICF$(S)                        &      2.36      &      1.93     \\
S/H, ($\times$10$^7$)           &$4.363\pm0.122$ &$3.431\pm0.264$ \\
log S/O                         &$-1.67\pm0.02$ &$-1.76\pm0.04$ \\ \\
Cl$^{2+}$/H$^+$, ($\times$10$^9$)&$2.846\pm0.560$&       ...      \\
$ICF$(Cl)                        &      1.48     &       ...      \\
Cl/H, ($\times$10$^9$)           &$4.207\pm0.827$&       ...      \\
log Cl/O                         &$ -3.68\pm0.09$&       ...      \\ \\
Ar$^{2+}$/H$^+$, ($\times$10$^8$)&$4.478\pm0.094$&$4.408\pm0.199$  \\
$ICF$(Ar)                        &      1.49     &      1.34     \\
Ar/H, ($\times$10$^8$)           &$6.680\pm0.287$&$5.900\pm0.812$  \\
log Ar/O                         & $-2.48\pm0.02$& $-2.52\pm0.06$  \\ \\
Fe$^{2+}$/H$^+$, ($\times$10$^7$)&$0.453\pm0.033$&       ...      \\
$ICF$(Fe)                        &      17.02    &       ...       \\
Fe/H, ($\times$10$^7$)           &$7.717\pm0.567$&       ...      \\
log Fe/O                         &$-1.42\pm0.03$&       ...      \\
\hline
\end{tabular}
\end{table}