What is the minimum amOunt of heat required to compEletly melt 20.0 grams of ice at its melting point?
Under 'latent heat' in one encyclopedia, it gives the latent
heat of fusion for water as 334 kJ/kg. This is the quantum of heat
needed to get a change of phase (solid to liquid) with no change of
temperature.
I'll leave you to do the math.