As altitude changes, the pressure changes. As altitude increases the pressure decreases. We can't get the water hot enough to break down the molecules in the potatoes. There is a relationship between attractive forces and boiling point. High viscosity indicates high attractive forces.
Surface tension is the energy required to increase the surface area of a liquid by a unit amount. .
Surface particles are different from internal particles with respect to attractive forces. On the surface the a.f. are not balanced, there is a net pull inward. The surface molecules are pulled into a skin or surrounding drop. There is a tendency for the surface area of a liquid to be reduced as much as possible. This is accomplished through the formation of a sphere since it gives the smallest surface area for a given volume of any geometrical shape.