Basically, because the skater will never use some kind of a boost, they will rely purely on forces. At the top of a slope, their kinetic E is zero, and their Potential E is as high as it will be.
The skater will not be able to ever get higher that the initial height without some kind of force helping it.
A. the number dots shown on the lewis dot diagrams for the element in the period
The answer should be A, they turn litmus paper blue!