If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Unit: Atomic structure and properties

AP Chem: SAP (BI), SAP‑1 (EU), SAP‑2 (EU), SAP‑3 (EU), SPQ (BI), SPQ‑1 (EU), SPQ‑2 (EU)

0

Possible mastery points

Moles and molar mass

AP Chem: SPQ (BI), SPQ‑1 (EU), SPQ‑1.A (LO), SPQ‑1.A.1 (EK), SPQ‑1.A.2 (EK), SPQ‑1.A.3 (EK)
Learn
Average atomic mass
(Opens a modal)
The mole and Avogadro's number
(Opens a modal)
Worked example: Calculating molar mass and number of moles
(Opens a modal)
Practice
Moles and molar massGet 3 of 4 questions to level up!

Mass spectrometry of elements

AP Chem: SPQ (BI), SPQ‑1 (EU), SPQ‑1.B (LO), SPQ‑1.B.1 (EK), SPQ‑1.B.2 (EK)
Learn
Isotopes
(Opens a modal)
Mass spectrometry
(Opens a modal)
Isotopes and mass spectrometry
(Opens a modal)
Worked example: Identifying an element from its mass spectrum
(Opens a modal)
Practice
Mass spectrometry of elementsGet 3 of 4 questions to level up!

Elemental composition of pure substances

AP Chem: SPQ (BI), SPQ‑2 (EU), SPQ‑2.A (LO), SPQ‑2.A.2 (EK), SPQ‑2.A.3 (EK)
Learn
Empirical, molecular, and structural formulas
(Opens a modal)
Worked example: Calculating mass percent
(Opens a modal)
Worked example: Determining an empirical formula from percent composition data
(Opens a modal)
Worked example: Determining an empirical formula from combustion data
(Opens a modal)
Practice
Elemental composition of pure substancesGet 3 of 4 questions to level up!

Composition of mixtures

AP Chem: SPQ (BI), SPQ‑2 (EU), SPQ‑2.B (LO), SPQ‑2.B.1 (EK), SPQ‑2.B.2 (EK)
Learn
Worked example: Calculating the mass of a substance in a mixture
(Opens a modal)
Worked example: Analyzing the purity of a mixture
(Opens a modal)
Practice
Composition of mixturesGet 3 of 4 questions to level up!

Atomic structure and electron configuration

AP Chem: SAP (BI), SAP‑1 (EU), SAP‑1.A (LO), SAP‑1.A.3 (EK)
Learn
The periodic table, electron shells, and orbitals
(Opens a modal)
Shells, subshells, and orbitals
(Opens a modal)
Introduction to electron configurations
(Opens a modal)
The Aufbau principle
(Opens a modal)
Valence electrons
(Opens a modal)
Electron configurations of ions
(Opens a modal)
Electron configurations of the 3d transition metals
(Opens a modal)
Practice
Atomic structure and electron configurationGet 3 of 4 questions to level up!

Periodic trends

AP Chem: SAP (BI), SAP‑1 (EU), SAP‑1.A (LO), SAP‑1.A.2 (EK), SAP‑1.A.4 (EK), SAP‑2 (EU), SAP‑2.A (LO), SAP‑2.A.2 (EK), SAP‑2.A.3 (EK), SAP‑3 (EU), SAP‑3.A (LO), SAP‑3.A.1 (EK)
Learn
Periodic trends and Coulomb's law
(Opens a modal)
Atomic and ionic radii
(Opens a modal)
Ionization energy: group trend
(Opens a modal)
Ionization energy: period trend
(Opens a modal)
First and second ionization energy
(Opens a modal)
Worked example: Identifying an element from successive ionization energies
(Opens a modal)
Electron affinity: period trend
(Opens a modal)
Electronegativity
(Opens a modal)
Practice
Periodic trendsGet 5 of 7 questions to level up!

Valence electrons and ionic compounds

AP Chem: SAP (BI), SAP‑2 (EU), SAP‑2.B (LO), SAP‑2.B.2 (EK), SAP‑2.B.3 (EK)
Learn
Valence electrons and ionic compounds
(Opens a modal)
Worked example: Finding the formula of an ionic compound
(Opens a modal)
Practice
Valence electrons and ionic compoundsGet 3 of 4 questions to level up!

Photoelectron spectroscopy

AP Chem: SAP (BI), SAP‑1 (EU), SAP‑1.B (LO), SAP‑1.B.1 (EK)
Learn
Introduction to photoelectron spectroscopy
(Opens a modal)
Photoelectron spectroscopy
(Opens a modal)
Practice
Photoelectron spectroscopyGet 3 of 4 questions to level up!

About this unit

This unit explores the atomic theory of matter, the foundational premise of chemistry. Learn about moles and molar mass, mass spectrometry, percent composition and empirical formulas, electron configurations, photoelectron spectroscopy, periodic trends, and more. Practice what you’ve learned and study for the AP Chemistry exam with more than 100 AP-aligned questions.
AP® is a registered trademark of the College Board, which has not reviewed this resource.