Will the formation of a dative bond change the oxidation number?

[coconut62]

Consider NH3, if it forms a dative bond with an H+ to form an ammonium ion, will the oxidation number of N change from +3 to +5? My reasoning is that it uses 5 electrons in bonding.

Is that correct?

 

[janhaa]

Read here:

http://www.chembuddy.com/?left=balancing-stoichiometry&right=oxidation-numbers-method

 

[janhaa]

furthermore

$$NH_3$$

$$NH_4^+$$