When something has a higher melting point does it mean it is more negative or less negative? Thanks

Question

I am studying for an exam and it asks to compare the MP of different substances. I understand the trends about when MP goes up and down, but I wanted to check what it means to increase the melting point.

Answer 1

The melting points of molecular compounds depend on the intermolecular attraction (aka van der Waals forces).  These include hydrogen bonding, dipole-dipole attractions, and London dispersion forces.

I have no idea what you mean by "more or less negative".  In order to compare melting points, you would compare the types of intermolecular bonding or the degree of each one.

For instance if you compared H2O, H2S and H2Se then water would have the highest MP because of the hydrogen bonding which is not present in the other two.  The next highest would be H2Se because of the greater contribution of London dispersion forces (which are present in all molecules) which depend (not on molecular weight, but) on the number of electrons and the volume that they occupy.

Answer 2

less negative is higher