What term describes the management of soil to prevent its destruction?
a. soil exhaustion
b. soil decomposition
c. soil conservation
d. soil fertility

C Soil conservation

Explanation:

Soil conservation is said to be done when the soil is protected from getting washed away due to erosion from climatic factors or other man made factors like using the soil too much for cultivation. Soil must also be protected from salts getting deposited in it at harmful levels.

Whenever the soil gets eroded due to environmental factors or when the soil is no longer able to support the growth of crops or vegetation, soil is said to be exhausted. It is soil exhaustion.

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.