Why does Cp spike at Tm(the point where the solid and liquid) for aliphatic chains under thermotrophic changes when changing from solid to liquid

When an electron is excited from n=2 to n=6, a photon of violet light is absorbed. If an electron on a Li^2+ ion is absorbed from n=4, which energy level must it rise to for violet of a similar wavelength is absorbed?

What does the activity coefficient tell us about the nature of the interactions present between the constituents in the liquid phase, and how is this related to the excess Gibbs energy.

If a dispersion of particles had zero charge (as measured by their zeta potential) and no surfactant coating, what would you expect dynamic light scattering to show in terms of effective hydrodynamic particle radius? A small negative value A value of zero A small positive value A large positive value A bimodal distribution of small and large value 25