Points A, B, C, and D are different points in the path of a roller coaster. At which of these points would a roller coaster car have the most kinetic energy?

Hi. where is the graph?

Well you can immediately rule out a and d because if a metal were to lose or gain protons, then it would become a different element all together. the answer here is b because the positive symbol with a number refers to how many electrons the metal can give away to become stable.

I'd say your answer would be the sides of a metal pan become hot when the pan is placed on the stove burner

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp