"EX"TRA!
'(<a href="http://www.j-archive.com/media/2008-04-15_DJ_07.jpg" target="_blank">Jon of the Clue Crew makes a chemical volcano.</a>)  Mixing hydrogen peroxide & yeast creates foam, steam & notably causes heat to be given off in <a href="http://www.j-archive.com/media/2008-04-15_DJ_07a.jpg" target="_blank">this</a> type of 10-letter chemical reaction'
an exothermic reaction