The NH4 asked about is the amonium ion, and it's written NH4+ to indicate it has a positive charge (+1). It's a cation. Wikipedia has more information on this chemically â¦ significant polyatomic ion, and you'll find that a link to that post is provided below. + 7 others found this useful.
Gilbert is a town in Maricopa County, Arizona, United States, just southeast of Phoenix, within the Phoenix metropolitan area.
Flagstaff is a city located in northern Arizona, in the southwestern United States. In 2013, the city's estimated population was 68,667. The combined metropolitan area of Flagstaff has an estimated population of 136,539. It is the county seat of Coconino County. The city is named after a ponderosa pine flagpole made by a scouting party from Boston (known as the Second Boston Party) to celebrate the United States Centennial on July 4, 1876.