[yewtzeee]

Different elements have different melting point,how about different isotopes?
do they have different melting point?

[ATMyller]

Yes they have. For example hydrogen has a melting point of about 14K whereas deuterium melts at 18.5K. Altought deuterium molecule has double the mass of hydrogen molecule so the diffrence is easy to notice along other differences like density, boiling point and heat capacity . With heavier elements the diffrence in melting points is usually too small to measure.