This would be more of a chemistry question. Remember magnesium has a charge of 2+, and would need to hand off its two extra electrons. Fluorine can only take one electron at a time, so there needs to be two fluorines to take one magnesium's 2 electrons.
With lithium, it has a +1 charge, so it has one extra electron, which it can hand off to just 1 fluorine atom.
Another way of looking at this is:

+ 2

= MgF2 (the charges must balance out to zero)

+

= LiF (the charges balance out to zero)
Answer:
The solution was to implement an absolute magnitude scale to provide a reference between stars. To do so, astronomers calculate the brightness of stars as they would appear if it were 32.6 light-years, or 10 parsecs from Earth.
Explanation:
Answer:
U2 = KAε0V2 / (2d)
Explanation:
The dielectric constant K just replaces the "3″ from Part B.
Thermal energy comes from the ,movement of particles which produces heat, the faster the movement is the more heat