Why are only certain parts of the moon lit up at different times?

Depends on the way the moon is facing the sun

Explanation: The moon is lit up by the way the moon is facing the sun. So, for example, when there is a full moon, the earth ius facing the sun compleatly. When there is a half, half of the moon is facing the sun.

Hope this helps

idk what the options are but

these is a strong electrostatic attraction between the ions hence a lot of energy is needed to overcome this attraction

this is why the boiling points are so high