The net positive charge flowing through a device is q(t) = 10 + 3t mc. find the current through the device

This chart represents the melting point of several substance. what besy explains the high melting point of the salt?

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Water is initially present in a state where its molecules are far apart. during a change of state, its molecules slow down. which change of state has most likely taken place? from a gas to a liquid from a liquid to a gas from a solid to a liquid from a gas to a plasma