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Chemistry 101 -- Periodic Trends
Recorded lectureFollow-up recommended
Professor Hall·May 5, 2026·52 min·10:00am - 10:52am
What happened in this session
- How atomic radius changes across periods and down groups
- Ionization energy trends and why noble gases have the highest values
- Electronegativity and its relationship to bond polarity
Concepts covered
Atomic RadiusReinforced
Ionization EnergyIntroduced
ElectronegativityIntroduced
Areas to strengthen
Ionization Energy
Unclear why ionization energy dips between Groups 2 and 3.
Why it matters: This exception appears on most AP Chemistry and SAT Chemistry exams.
The lecture covered three major periodic trends. Atomic radius was mostly review and Alex handled it well. Ionization energy and electronegativity were new -- both were introduced for the first time. There is one gap to address: why ionization energy drops between Groups 2 and 3. That exception trips up a lot of students and it shows up on AP Chemistry.
All concepts
Atomic RadiusReinforced
Ionization EnergyIntroduced
ElectronegativityIntroduced
Open gaps from this session
Ionization Energy
Unclear why ionization energy dips between Groups 2 and 3.
Why it matters: This exception appears on most AP Chemistry and SAT Chemistry exams.
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Before your next session
Review the ionization energy exceptions before the next lab
Before your next session -- Mon Jun 2, 4:00pm
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