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.
Gilbert, Arizona - Gallery of historic buildings. 1  Gilbert Elementary School was built in 1913. 2  Gilbert High School was built in 1920. 3  The Gilbert Water Tower was built in 1925. 4  Gilbert's first jail house was built in 1918 and later used as a pump house. 5  The Tone Building was built in 1929 and now houses Joe's Real BBQ Restaurant.