The ability of a system to do work; required for changes to happen within a system

it may be wrong but i think its a

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

i will answer your question if you answer mine

as we know our atmosphere or air have different levels. every level has other gasses, and every gas has another permeability. when the light comes from lower permeability to higher permeability, it changes its direction. so that means that when the light comes from the moon to the earth, it changes it's direction many more times. it basically means that the shape of the light part of the moon is changed on the earth.

hope this ! this is not copied! search it up, it's free of plagiarism!