Ammonium
Appearance
Ammonium (NH4+) is a group of atoms that behave like an alkali metal. It is found ionized in various salts, such as ammonium bicarbonate and ammonium chloride. Ammonium can be formed by disolving ammonia in water, forming ammonium hydroxide.
Ammonium has been isolated in amalgam, but not as a solid metal.
Ammonium is also found in urine.