Explanation:
Most reagent forms are going to absorb water from the air; they're called "hygroscopic". Water presence can have a drastic impact on the experiment being performed For fact, it increases the reagent's molecular weight, meaning that anything involving a very specific molarity (the amount of molecules in the final solution) will not function properly.
Heating will help to eliminate water, although some chemicals don't react well to heat, so it shouldn't be used for all. A dessicated environment is simply a means to "dry." That allows the reagent with little water in the air to attach with.
The subatomic particle involved in chemical bonding is the electron. Electrons are the smallest of all subatomic particles and orbit the nucleus in discrete energy levels called shells. Electrons are negatively charged and the nucleus is positively charged due to the protons.
Explanation :
The balanced chemical reaction will be,

By the stiochiometry, 3 moles of solid copper(II)oxide react with 2 moles of ammonia gas to give 3 moles of copper metal, 1 mole of nitrogen gas and 3 moles of liquid water.
The states of matter of each elements and compound is,
Copper(II)oxide is in solid state
Ammonia is in gaseous state
Copper metal is in solid state
Nitrogen is in gaseous state
Water is in liquid state
The correct answer is that last one