Questions

Arakan yoma is the extension of the himalayas located in Myanmar. The Arakan Mountains are also known as the Rakhine Mountains.

These are a mountain range in western Myanmar, between the coast of Rakhine State and the Central Myanmar Basin, in which the Irrawaddy River flows.

NH3, Ammonia is a neutral compound as the individual oxidation numbers elements that make up the compound NH3 are Nitrogen (N) and Hydrogen (H) sum to zero. 

We do not speak of the oxidation number of a molecule. We can speak of the oxidation numbers of the individual elements that make up the compound.

Here the oxidation number of Nirogen is -3 and that of Hydrogen is +1.

Now, NH3 = 1(-3) + 3(+1) = -3 + 3 = 0.