What type of intermolecular forces must be overcome to:a: boil waterb. melt NaClc. sublime

a. To boil water, you must overcome Hydrogen bonds. Water molecules are polar and form hydrogen bonds, which are a type of dipole-dipole interaction. These are relatively strong intermolecular forces, and overcoming them requires a significant amount of energy, which is why water has a relatively high boiling point.

b. To melt NaCl (table salt), you must overcome ionic bonds. NaCl is an ionic compound, meaning it's composed of positively and negatively charged ions. These ions are held together by ionic bonds, which are very strong and require a lot of energy to break.

c. To sublime a substance (change it directly from a solid to a gas), you must overcome whatever intermolecular forces are present in the solid. This could be London dispersion forces, dipole-dipole interactions, hydrogen bonds, or ionic bonds, depending on the substance. The specific type of intermolecular force can vary widely, as many different types of substances can undergo sublimation.