What three states are called middle atlantic states

The rocky mountain system stretching from canada to new mexico is a string of mountains running along the wester united states. what factors would mostly cause this arrangement of mountains? intense pressure undemeath a tectonie plate that could not breakthrough the rock subduction of a tectonic plate, which pushed up a neighboring plate into mountains two plates located at a diverging boundary with a third plate rising between them two plates that melted into molten rock, which later cooled into the shape of mountains

As water is cooled from 4 c to 0 c its density

What was the great rift valley formed by