Which of the following statements describes a difference between the continents on Earth as scientists think they existed 540 million years ago and their existence today?

A) The continents were influenced by underlying convection currents in the mantle 540 million years ago; today this factor is no longer an influence.
B) The continents were located mainly in the Southern Hemisphere 540 million years ago; today they are distributed throughout both hemispheres.
C) The continents were moving 540 million years ago; today they no longer move.
D) The continents were devoid of life 540 million years ago; today they are full of living organisms.

when it gains or loses electrons

the amount of current in the coil

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.