I would assume that the magnesium would have to come into contact with an ion in order to become a magnesium ion.
The relationship between frequency and wavelength for an electromagnetic wave is

where
f is the frequency

is the wavelength

is the speed of light.
For the light in our problem, the frequency is

, so its wavelength is (re-arranging the previous formula)
Answer:
Part a)

Part b)

Explanation:
Time period of sun is given as



Now the radius of the orbit of sun is given as



Part a)
centripetal acceleration is given as




Part b)
orbital speed is given as



Answer:
When you have a cloudy night, the clouds prevent heat from escaping through the atmosphere and into space.
The clouds act like a blanket and trap the heat it, and that is why every time you have a cloudy night, it is always warmer than a clear night.