All topicsAtoms of which element release the most energy when an electron is added to them in the gas phase?2018 national · question 4612%In which list are the ions ranked in order of increasing ionic radius?2019 national · question 4417%Which diatomic molecule has the greatest bond dissociation enthalpy?2022 national · question 4525%
Atomic structure and periodicity
This is block 8 of 10, questions 43–48 on both the local section exam and national Part I. Across the 40 national questions where ACS published item statistics, qualifiers answered 47% correctly, which makes it the fourth hardest of the 10.
What it covers
quantum numberselectron configurationperiodic trendsionization energyphotoelectron spectroscopyatomic spectranuclear chemistry
Where qualifiers lose points
% who got it rightThese are the atomic structure and periodicity questions the fewest national qualifiers answered correctly. If you can do these, the block is not your problem.
Every question is from a published past exam and carries its source. Practice adapts to what you miss, and anything you get wrong comes back on a spaced schedule. No account needed. See the other nine blocks.