Which of the following substances would have the greatest dispersion forces?

• A. Ne
• B. Xe
• C. Ar
• D. He

Answer: (B)

Verified step by step guidance

1. Understand that dispersion forces (also known as London dispersion forces) are a type of intermolecular force that arise due to temporary fluctuations in electron distribution within atoms or molecules, creating instantaneous dipoles.
2. Recognize that dispersion forces increase with the size and polarizability of the atom or molecule. Larger atoms with more electrons have more easily distorted electron clouds, leading to stronger dispersion forces.
3. Compare the given noble gases: He, Ne, Ar, and Xe. Note their relative atomic sizes and number of electrons: He < Ne < Ar < Xe in terms of size and electron count.
4. Conclude that since Xe is the largest atom with the most electrons among the options, it will have the greatest polarizability and thus the strongest dispersion forces.
5. Therefore, the substance with the greatest dispersion forces is Xe.