Which of the following must be true of a quantized measurement? a. it cannot be precisely known. b. it can only be a measurement of energy. c. it must have a smallest possible value. d. it could have any value, limited by the accuracy of your equipment.

Quantization is a continuous range of values into a finite range of discreet values.

which means we have many values which are continuous but all such values are in discrete forms of fixed numbers.

Like for an example let say the energy of electron inside atom is quantized which means its energy will be in the form of fixed number but there will be large such groups possible.

So quantized value is the smallest possible value which can be possible and such a group of small values can be add together to form a large number

So correct answer is

C.It must have a smallest possible value.

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.