The melting point of xenon tetrafluoride (${XeF}_4$) is significantly higher than that of sulfur tetrafluoride (${SF}_4$).

Explain why the melting points of these two compounds are different.

In your answer you should:

• Give the shape of each molecule and explain why each has that shape.
• Explain how the shape of each molecule determines its polarity.
• Explain how these factors influence the intermolecular forces and the difference in melting points.

\text{}