I need help :(

According to each substances heat of fusion, which of the items below requires more heat to be added per gram of substance to go from solid to liquid? silver sulfur water lead

Which statement explains why the bonds between non metals tend to be covalent? the bonds are found to be nondirectional they have large differences in electronegativity they have small differences in electronegativity they have ions that produce an electrostatic pull

Which substance has non polar covalent bonds