Why does nitrogen show only reducing properties in ammonia NH3, and only oxidizing properties in nitric acid NHO3?

1. Elements in higher oxidation states are only capable of accepting electrons, that is, exhibiting the properties of oxidizing agents.

2. If an element has the lowest oxidation state, then it can only increase it, acting as a reducing agent.

3. Determine the oxidation state of nitrogen in the substances presented:
N-3H3, (- 3) is the minimum oxidation state of nitrogen, therefore it exhibits only reducing properties;
HN + 5O3, (+5) – the maximum degree that allows nitrogen to be only an oxidizing agent.