The oxidation number of nitrogen in the nitrate ion NO3- is 5
Nitrate ion is a anion. Nitogen shows +5 in this ion.
Phosphorus in PCl5 Nitrogen in Nitrate (NO3-) ion
+1 for H -2 for O +5 for N
The two nitrogen atoms are in different oxidation states. The one in the ammonium ion (NH4+) is in the 3- oxidation state while the one in the nitrate ion (NO3-) is in the 5+ oxidation state.
If you are referring to the nitrate ion, NO3-, the oxidation number of oxygen would be O2- and nitrogen would be N5+. If you are talking about nitrogen trioxide NO3, the oxidation number of oxygen would be O2- and nitrogen would be N6+. Edit: Nitrogen trioxide does not exist in its free state.
Nitrogen's oxidation number is -4.Carbon's oxidation number is +3.The cyanide ion has -1 charge. Nitrogen is in -3 state. By balancing the charges: the oxidation number of carbon is +4.
Calcium is a element. Nitrate is a ion. Calcium shows +2.
Pure element has zero oxidation number. When forming ions it is equal the charge of ion.
In nitrate ion (NO3-1) the formal charge of nitrogen is +5.
In the NO3- ion nitrogen is in its 5+ oxidation state.