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.
* Students from any other county in Arizona are considered Maricopa County residents (in county) due to a reciprocal arrangement with that county. Reciprocal agreements allow for in-county tuition rates for residents of all Arizona counties except Apache or Greenlee counties without an Out-of-County Residence Affidavit.