AP Chemistry · Unit 1: Atomic Structure and Properties
1.7 Periodic Trends
In short
You must understand the organization of the periodic table based on recurring properties, ground-state electron configurations, and completely or partially filled shells. You must be able to predict and qualitatively explain trends in ionization energy, atomic and ionic radii, electron affinity, and electronegativity using Coulomb's law, the shell model, shielding, and effective nuclear charge.
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What else do you need to know about Periodic Trends?
You should also use periodicity to estimate property values when data is absent. Writing the electron configuration of elements that are exceptions to the aufbau principle is explicitly excluded and will not be assessed.
Can you do these?
- I can qualitatively explain periodic trends using Coulomb's law, the shell model, shielding, and effective nuclear charge.
How is Periodic Trends tested on the exam?
Many students struggle by merely memorizing periodic trends rather than explaining the underlying electrostatic interactions. Exam questions will require you to justify claims with evidence, connecting periodic trends to the shell model, Coulomb's law, and elements of quantum theory. Explaining exceptions to trends using these principles is also a common area of difficulty that examiners will test.
Free practice questions with full explanations, and instant marking of your free-response answers.
Periodic Trends: common questions
What do you need to know about Periodic Trends for AP Chemistry?
You must understand the organization of the periodic table based on recurring properties, ground-state electron configurations, and completely or partially filled shells. You must be able to predict and qualitatively explain trends in ionization energy, atomic and ionic radii, electron affinity, and electronegativity using Coulomb's law, the shell model, shielding, and effective nuclear charge.
How is Periodic Trends tested on the AP Chemistry exam?
Many students struggle by merely memorizing periodic trends rather than explaining the underlying electrostatic interactions. Exam questions will require you to justify claims with evidence, connecting periodic trends to the shell model, Coulomb's law, and elements of quantum theory.
How do I know I have mastered Periodic Trends?
Check you can do each of these: qualitatively explain periodic trends using Coulomb's law, the shell model, shielding, and effective nuclear charge.
Where does Periodic Trends fit in AP Chemistry?
Periodic Trends is topic 1.7 in Unit 1: Atomic Structure and Properties of AP Chemistry.
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