CHEMISTRY · Multi-part · A Level · Chemistry · Periodicity and periodic trends · Periodicity and periodic trends
Problem
Halogens are powerful oxidizing agents, whereas noble gases are largely inert, and alkali metals readily form cations but not anions.
Use the concept of electron affinity to relate these macroscopic observations to atomic-level properties.
(a) Explain how the magnitude and sign of the electron affinity of a halogen are related to its tendency to oxidize other species.
(b) Give two reasons why noble gases have electron affinities that are close to zero or slightly positive, and relate this to their lack of chemical reactivity.
(c) In the formation of NaCl(s) from its elements, identify which element undergoes reduction. Use comparative electron affinities to justify your answer.