AP Chemistry Unit 9 Vocabulary: Atomic Structure & Periodic Properties
You are responsible for knowing the meaning and applications of each of the following terms.
You can receive extra credit by creating numbered flashcards, one for each word (the word is on
one side and the definition is on the other).
1. Dalton’s Atomic Theory
2. Electronic Structure
3. Wavelength
4. Frequency
5. Plank’s Constant
6. Atomic Spectrum
7. Orbitals
8. Bohr’s Model
9. Wave Mechanical Model
10. Ground State
11. Excited State
12. de Broglie’s Matter Wave Theory
13. Momentum
14. Heisenberg’s Uncertainty Principle
15. Pauli Exclusion Principle
16. Magnetic Quantum Number
17. Principle Quantum Number (Electron
Shell)
18. Angular Momentum Quantum Number
(Subshell)
19. Spin Quantum Number
20. Electron Configuration
21. Valence Electrons
22. Core Electrons
23. Hund’s Rule
24. Aufbau Principle
25. Main Group Elements
26. Transition Elements
27. Lanthanide (Rare Earth) Elements
28. Actinide Elements
29. Alkali Metals
30. Alkaline Earth Metals
31. Halogens
32. Noble (Inert) Gases
33. Metalloids
34. Allotrope
35. Atomic Radius
36. Ionization Energy
37. Electron Affinity
38. Electronegativity
39. Metallic Character
What you need to know for Unit 9:
Unit 9 relates to Chapters 6 & 7 in your textbook.
 Describe the electromagnetic spectrum
 Describe the relationship between frequency and wavelength and calculate both
 Describe the relationship between energy and wavelength of light and be able to order the light
based on both
 Describe the dual nature of light
 Describe diffraction
 Explain how line spectra of the elements relate to the idea of quantized energy states of electrons
in atoms
 Describe the quantum mechanical model of the atom including the Schrodinger equation and
wave functions
 Understand Heisenberg’s Uncertainty Principle and how it limits how precisely we can specify
the position and momentum of subatomic particles such as electrons
 Describe orbital shape and energies of an atom
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Describe quantum numbers and how they relate to orbitals
Describe electron spin and the Pauli Exclusion Principle
Draw an orbital diagram
Write electron configurations and use the periodic table to write abbreviated electron
configurations
Write electron configurations of ions
Describe the problems of the Schrödinger equation with polyeletronic ions
Describe the periodic table and the Aufbau Principle
Describe Hund’s Rule and electron configuration
Describe periodic trends such as atomic radii, ionization energy, electron affinity,
electronegativity, reactivity, oxidation numbers, and ionic radii and how each are related to
chemical reactivity and physical properties
Understand how radii change as atoms become ions
Understand how the ionization energy changes as we remove excessive electrons and recognize
that it jumps as when removing a core electron
Name and describe properties of main group elements (alkali metals, alkaline earth metals,
transition metals, halogens, and noble gases)
There is also a list of important people who contributed to the Modern Atomic Theory. You will
need to know what each one did.
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John Dalton: Atomic Theory
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Michal Faraday: electric current can cause chemical reactions
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Sir William Crookes: cathode ray tube
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J.J. Thomson: used cathode ray tube to discover electrons and their mass; also created the
plum pudding model of the atom
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Robert Millikan: oil drop experiment to find charge of electrons
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Ernest Rutherford: gold foil experiment to find that atoms had a small, positive, densely
packed nucleus and that atoms are mostly empty space; also discovered the proton
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James Chadwick: discovered the neutron
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Johann Balmer: used hydrogen to find that light wavelength related to numbers
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Johannes Rydberg: created equation to make Blamer’s concept apply to all elements
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Niels Bohr: created “solar system model” of atoms where electrons go around nucleus in
different orbitals
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Max Planck: light is contained in particles called photons
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Louis de Broglie: if light travels in waves then electrons (matter) can travel in waves
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Erwin Schrödinger: created wave-mechanical, or quantum mechicanl, model
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Werner Heisenberg: created uncertainty principle where the position and momentum of an
electron can not be known at the same time