(N/A) $(i)$ Scattering of light: It is the phenomenon of the redirection of light in different directions by the particles (such as atoms,molecules,dust,or smoke) present in the atmosphere.
$(ii)$ Why the sky appears blue: The fine particles in the atmosphere have a size smaller than the wavelength of visible light. These particles scatter light of shorter wavelengths (like blue and violet) much more strongly than light of longer wavelengths (like red). Since blue light has a shorter wavelength,it is scattered the most,which is why the sky appears blue to our eyes.
$(iii)$ Why the sun appears reddish at sunrise: At sunrise,the sun is near the horizon. Sunlight has to travel through a much thicker layer of the atmosphere to reach the observer. During this long journey,most of the blue and shorter wavelength light is scattered away by the atmospheric particles. Only the light of longer wavelengths,such as red,reaches our eyes,which is why the sun appears reddish at sunrise.