No. It is an ion with two different elements: nitrogen and oxygen.
(NO3)- is the anion nitrate.
It could be either. For example, a molecule of O2 or Cl2 is an element, but one of CH4 or NO3 is a compound.
element
You can treat a polyatomic ion as an element when balancing equations. The following example involves the polyatomic ion NO3-. Notice that the entire polyatomic ion is placed in parentheses and given its own subscript. 2Al(s) + 3Mg(NO3)2(aq) --> 2Al(NO3)3(aq) + 3Mg(s)
Oxygen is a gas.
Copper: 2+Oxygen: 2-Nitrogen: 5+
Mg(NO3)2 {note correct case for "O"} is not an element at all. Instead it is a compound of three elements, magnesium, nitrogen, and oxygen.
In each molecule of NO3, there is one nitrogen atom and there are three oxygen atoms.
NO3- stands for nitrate anion. It has to have one negative charge ( .- ) in superscript position.
an element
It could be either. For example, a molecule of O2 or Cl2 is an element, but one of CH4 or NO3 is a compound.
Calcium nitrate is a compound: Ca(NO3)2.
element
A representative element.
halogen
yes
You can treat a polyatomic ion as an element when balancing equations. The following example involves the polyatomic ion NO3-. Notice that the entire polyatomic ion is placed in parentheses and given its own subscript. 2Al(s) + 3Mg(NO3)2(aq) --> 2Al(NO3)3(aq) + 3Mg(s)
a gas Oxygen is classified as a nonmetal element within the oxygen family.