A catalyst in the same phase (usually liquid or gas solution) as the reactants and products is called homogeneous catalyst. A catalyst that is in a separate phase from the reactants is said to be a heterogeneous, or contact, catalyst. Contact catalysts are materials with the capability of adsorbing molecules of gases or liquids onto their surfaces. An example of heterogeneous catalysis is the use of finely divided platinum to catalyze the reaction of carbon monoxide with oxygen to form carbon dioxide.
A juror may be excused from the panel if it is shown that the juror cannot act impartially concerning the case to be heard. In addition, each side is allowed to remove a given number of jurors from the panel without having to show any reason. The trial jury will be the first 6 to 12 of the remaining jurors on the panel. If you are not chosen for a jury, you will be sent home. If you have been chosen to serve on a jury, you will now see our justice system in action. Visit The Trial Process and Tips for Reporting and Serving for more information.
1 Grand Jurors do not serve on a trial, like Trial Jurors. Rather, they evaluate evidence presented by the prosecutor and decide if it is sufficient to indict (bring a criminal charge against) a person or corporation.  The grand jury does not decide the guilt or innocence of the accused.