The table below compares some of the properties of three different objects that are all made of pure substances.

Object Melting Point Mass Volume
X 327.5°C 10 g 25 cm3
Y 1,083°C 10 g 12.5 cm3
Z 327.5°C 5 g 12.5 cm3

According to the table, which of the following is most likely true?