Answer : The correct option is, (a) Synthesis
Explanation :
Synthesis reaction : A chemical reaction where multiple substances or reactants combine to form a single product.
It is represented as,

Combustion reaction : A chemical reaction in which a hydrocarbon react with the oxygen to give product as carbon dioxide and water.
It is represented as,

Single replacement reaction : A chemical reaction in which the more reactive element replace the less reactive element.
It is represented as,

In this reaction, A is more reactive element and B is less reactive element.
Double replacement reaction : It is a type of chemical reaction where a positive cation and a negative anion of two reactants exchange places to form two new products.
It is represented as,

(X and A are the cations, Y and B are the anions)
The given reaction is, 
In this reaction, calcium combine with the chloride to form calcium chloride as a product.
Hence, the given type of reaction is a synthesis reaction.
Answer:
3
Explanation:
Since the atom has three electrons, it has a -3 electrical charge. Since atoms are neutral, 3 protons are needed to get the charge back to 0.
Transverse wave is <span>a wave vibrating at right angles to the direction of its propagation.
In short, Your Answer would be Option B
Hope this helps!</span>
Answer:
D
Explanation:
An atom can be considered unstable in one or two ways. If it pickes up or loses an electron,it becomes electrically charged and highly reactive.Intabability can also occur in the nucleus when the number of protons and neutrons is unbalanced.