\begin{table}%t4
 %%\centering

\par
 \caption{\label{tab:chem}Abundances relative to the Sun for $20$ elements in \corots, 
with the number of lines used for each element.}
% 
 % narrow table: default is tabcolsep = 6pt
\small
\begin{tabular}{llr|llr}
\hline
\hline
  {C  \sc   i} &  $  +0.06        $  &   1   & {Mn \sc   i} &  $  +0.16        $  &   2 \\
  {Na \sc   i} &  $  +0.11        $  &   1   & {Fe \sc   i} &  $  +0.13\pm0.04 $  & 143 \\
  {Mg \sc   i} &  $  +0.13        $  &   1   & {Fe \sc  ii} &  $  +0.13\pm0.04 $  &  16 \\
  {Al \sc   i} &  $  +0.12        $  &   2   & {Co \sc   i} &  $  +0.10\pm0.05 $  &   6 \\
  {Si \sc   i} &  $  +0.15\pm0.04 $  &   6   & {Ni \sc   i} &  $  +0.12\pm0.04 $  &  40 \\
  {Ca \sc   i} &  $  +0.15\pm0.04 $  &   7   & {Cu \sc   i} &  $  +0.14        $  &   1 \\
  {Sc \sc   i} &  $  +0.10        $  &   1   & {Zn \sc   i} &  $  +0.10        $  &   1 \\
  {Sc \sc  ii} &  $  +0.06\pm0.05 $  &   3   & {Sr \sc   i} &  $  +0.32        $  &   1 \\
  {Ti \sc   i} &  $  +0.11\pm0.04 $  &  37   & {Y  \sc  ii} &  $  +0.11\pm0.09 $  &   3 \\
  {Ti \sc  ii} &  $  +0.09\pm0.04 $  &   8   & {Zr \sc   i} &  $  -0.00        $  &   2 \\
  {V  \sc   i} &  $  +0.15\pm0.05 $  &   3   & {Ba \sc  ii} &  $  +0.24        $  &   1 \\
  {Cr \sc   i} &  $  +0.09\pm0.04 $  &   8   &              &                     &     \\
  {Cr \sc  ii} &  $  +0.10\pm0.04 $  &   2   &              &                     &     \\
\hline
\end{tabular}
\end{table}