Group 18 Elements

To evaluate the given statements, let's begin by understanding the properties of noble gases and how they relate to the boiling points and intermolecular forces.

1. Noble Gases: Noble gases, which include helium, neon, argon, krypton, xenon, and radon, are found in Group 18 of the periodic table. These gases are known for their chemical inertness and are monoatomic at room temperature.
2. Boiling Points of Noble Gases: The boiling points of noble gases are generally low. For example, helium has one of the lowest boiling points of any element at around . This is because their atoms are only weakly attracted to each other by Van der Waals forces (specifically dispersion forces), which are weak compared to the covalent or ionic bonds found in other compounds.
3. Statement Analysis:
   • Statement I: This statement claims that noble gases have very high boiling points. This is incorrect because, in reality, noble gases have low boiling points due to weak intermolecular forces.
   • Statement II: It states that noble gases are monoatomic and are held together by strong dispersion forces, leading to high boiling points. While the statement correctly identifies noble gases as monoatomic, it incorrectly describes the strength of the forces involved. Dispersion forces are indeed present, but they are not strong; thus, noble gases have low boiling points. Hence, this statement is also false in conclusion.
4. Conclusion: Both Statement I and Statement II are false. Noble gases do not have high boiling points due to their weak intermolecular forces.