A mixture containing a complex of it and two ammonia molecules can differentiate between aldehydes and ketones, and is called the Tollens' reagent.
A very mild alcohol oxidant consists of this element's carbonate on a Celite filter, and is called Fetizon's reagent. Iron-molybdenum catalysts and catalysts of this element are used in the two methods of industrially synthesizing formaldehyde from methanol. Ethylene oxide is produced from ethylene using a catalyst of this element. This element's iodide is effective at inducing precipitation in clouds, and this metal forms an alloy with gold called electrum. A mixture containing a complex of it and two ammonia molecules can differentiate between aldehydes and ketones, and is called the Tollens' reagent. For 10 points, name this second member of the copper family, before gold, which is also used for currency purposes.
A very mild alcohol oxidant consists of this element's carbonate on a Celite filter, and is called Fetizon's reagent.
silver [or Ag]