Magnesium atom has 2 valence electrons in its third shell.
which is a true statement about what happens when it forms an ion?
a. it will be an anion.
b. it will have more electrons than protons.
c. it will gain 2 electrons in order to become stable.
d. it will lose 2 electrons in order to become stable.

D.It will lose 2 electrons in order to become stable.

Explanation:

It will lose 2 electrons in order to become a stable element or to attain the octet electronic configuration which makes it stable

D. It will lose two electrons in order to become stable

Explanation:

Magnesium has two electrons in its valence shell and since it needs to acquire am correct shell, it's easier and faster to lose two electrons than gain six more electrons. Magnesium needs to lose electrons during chemical reaction for bonding to take place while forming an intermediate Mg²+ ion.

NB: all elements of group 2 elements lose their two valence electrons in their outer shell to form chemical bond during chemical reactions

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.