The ammonium ion has a formula of NH4+ and has a positive charge so it is a cation.
Meaning & History. From a Germanic name meaning eagle power, derived from the elements arn eagle and wald power. The Normans brought it to England, where it replaced the Old English cognate Earnweald.It died out as an English name after the Middle Ages, but it was revived in the 19th century.aints bearing the name include an 8th-century musician in the court of Charlemagne and an 11th-century French bishop who is the patron saint of brewers. It was also borne by Arnold of Brescia, a 12th-century Augustinian monk who rebelled against the church and was eventually hanged.
The place is recorded in the Domesday Book of 1086 as Rovecestre. Rochester in Northumberland is thought to have been named from the place in Kent, or the first element may be the Old English hroc, rook. The modern surname from either of these sources can be found as Rochester, Rogister, and Rossiter.