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.
In the state legislature, Arnold is in the 8th Senate District, represented by Republican Tom Berryhill, and the 5th Assembly District, represented by Republican Frank Bigelow. Federally, Arnold is in California's 4th congressional district, represented by Republican Tom McClintock.