COMPOUNDS IN ACTION
'(<a href="http://www.j-archive.com/media/2006-10-23_J_07.jpg" target="_blank">Cheryl of the Clue Crew reports from inside a science lab.</a>)  When hydrogen sulfide in the air reacts with silver, it creates a <a href="http://www.j-archive.com/media/2006-10-23_J_07a.jpg" target="_blank">coating</a> called silver sulfide, better known by this one word'
tarnish