Answer : The correct option is, (C)
Explanation :
A. 
This is synthesis reaction in which the two or more reactant react to give a single product.
B. 
This is combination reaction in which the two reactants combine to form a single product.
C. 
This is a neutralization reaction in which an acid react with a base to give a salt and water as a product.
D. 
This is a double displacement reaction in which the positive cation and negative anion of two reactants exchange their places to give two new products.
Hence, the reaction (C) is a neutralization reaction.
<u>Answer:</u>
<u>For 1:</u> The product is phosphoric acid and the solution is acidic in nature.
<u>For 2:</u> The product is sodium hydroxide and the solution is basic in nature.
<u>For 3:</u> The product is nitric acid and the solution is acidic in nature.
<u>Explanation:</u>
For the given options:
(1): When diphosphorus pentoxide reacts with water, it leads to the formation of phosphoric acid, which makes the solution acidic in nature.
The chemical equation for the reaction follows:

(2): When disodium oxide reacts with water, it leads to the formation of sodium hydroxide, which makes the solution basic in nature.
The chemical equation for the reaction follows:

(3): When dinitrogen pentoxide reacts with water, it leads to the formation of nitric acid, which makes the solution acidic in nature.
The chemical equation for the reaction follows:

It depends on mass and velocity.
In this case as the ice is solid its particles are stationary that it have zero velocity hence its kinetic energy is too zero.
Answer:option a
Answer: All solids absorb heat as they melt to become liquids.
Explanation:
Energy is the correct answer. I hope I helped you