Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Experimental reaction of $$\mathrm{CH}_{3} \mathrm{Cl}$$ with aniline and anhydrous $$\mathrm{AlCl}_{3}$$ does not give $$o$$ and $$p$$-methylaniline.

Reason (R): The $$-\mathrm{NH}_{2}$$ group of aniline becomes deactivating because of salt formation with anhydrous $$\mathrm{AlCl}_{3}$$ and hence yields $$m$$-methyl aniline as the product.

In the light of the above statements, choose the most appropriate answer from the options given below :

Chlorophyll extracted from the crushed green leaves was dissolved in water to make $$2 \mathrm{~L}$$ solution of Mg of concentration $$48\, \mathrm{ppm}$$. The number of atoms of $$\mathrm{Mg}$$ in this solution is $$x \times 10^{20}$$ atoms. The value of $$x$$ is ___________. (Nearest Integer)

(Given : Atomic mass of $$\mathrm{Mg}$$ is $$24 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1}$$ )

The wavelength of an electron and a neutron will become equal when the velocity of the electron is $$x$$ times the velocity of neutron. The value of $$x$$ is ____________. (Nearest Integer)

(Mass of electron is $$9.1 \times 10^{-31} \mathrm{~kg}$$ and mass of neutron is $$1.6 \times 10^{-27} \mathrm{~kg}$$ )

$$2.4 \mathrm{~g}$$ coal is burnt in a bomb calorimeter in excess of oxygen at $$298 \mathrm{~K}$$ and $$1 \mathrm{~atm}$$ pressure. The temperature of the calorimeter rises from $$298 \mathrm{~K}$$ to $$300 \mathrm{~K}$$. The enthalpy change during the combustion of coal is $$-x \mathrm{~kJ} \mathrm{~mol}^{-1}$$. The value of $$x$$ is ___________. (Nearest Integer)

(Given : Heat capacity of bomb calorimeter $$20.0 \mathrm{~kJ} \mathrm{~K}^{-1}$$. Assume coal to be pure carbon)