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 -C They are defined by the number of electrons.
An orbital is a function that describes the probability of finding the electron with certain energy at certain distance from the nucleus therefore, it is defined by the number of electrons.
Answer:
The speed of wavelength is 3.0 ×10³ m/s.
Explanation:
Given data:
De Broglie wavelength = 132 pm (132×10⁻¹² m)
Speed of wavelength = ?
Solution:
Formula:
λ = h/mv
λ = wavelength
h = planck's constant
m = mass of proton
v = speed
now we will put the values in formula.
132×10⁻¹² m = 6.63 ×10⁻³⁴ j.s / 1.67 ×10⁻²⁷ kg × v
v = 6.63 ×10⁻³⁴ j.s / 1.67 ×10⁻²⁷ kg × 132×10⁻¹² m
j = kg m²/s²
v = 6.63 ×10⁻³⁴ kg m²/s / 1.67 ×10⁻²⁷ kg × 132×10⁻¹² m
v = 6.63 ×10⁻³⁴ kg m²/s / 220.44 ×10⁻³⁹ kg.m
v = 0.03×10⁵ m/s
v = 3.0 ×10³ m/s
The speed of wavelength is 3.0 ×10³ m/s.