The Online AP Chemistry Course

Explore how measurements combine a number with a unit, why the international system of units standardizes science, and how prefixes create practical derived units.

Learn dimensional analysis to convert units using conversion factors, cancel units, and set the larger unit to one, with examples from cm to inches, km to miles, and mpg.

Master dimensional analysis and unit conversion techniques using metric prefixes, convert between centimeters, meters, and nanometers, and solve practical problems involving volume, density, and apothecary and troy weight units.

Explore the three fundamental chemical laws: conservation of mass, definite proportions, and multiple proportions. See how mass is conserved, compounds have fixed element ratios, and ratios are whole numbers.

Explore John Dalton's atomic theory, detailing that all matter consists of atoms, atoms of a given element are identical, compounds form from different elements, and chemical reactions are reorganizations.

Ernest Rutherford, a Cambridge professor, conducted the gold foil experiment to reveal a positively charged nucleus. He proposed a nuclear model with a central nucleus and electrons on the outside.

Explore Rutherford diagrams and Lewis structures, learn to build electron shells around a nucleus, identify valence electrons and full octets, and connect these concepts to element reactivity.

Explore the periodic table by examining groups and periods, learn how columns and rows define similar properties, and identify alkali metals, alkaline earth metals, transition metals, halogens, and noble gases.

Learn to name ionic compounds by identifying the cation and anion, using -ide endings for monoatomic ions, and applying polyatomic ions such as nitrate and ammonium, balancing charges.

Explore why transition metals need roman numerals to show charge, and how covalent compounds use prefixes to name two nonmetals, with copper(II) chloride and copper(I) chloride as examples.

Explore isotopes, elements with the same atomic number but different numbers of neutrons, such as hydrogen and carbon isotopes, and distinguish mass number from atomic mass.

Learn Avogadro's number and the mole, converting atomic mass units to grams, and using molar mass to find how many grams correspond to a given number of particles.

Apply mole calculations from Avogadro's number to convert between atoms, moles, and mass, with practice problems on iron, carbon, diamond, and chloral hydrate.

Explore limiting and excess reagents with a hydrogen–chlorine reaction, showing how chlorine limits product formation and hydrogen remains in excess, using mole ratios and conservation of mass.

Master the first law of thermodynamics: energy cannot be created or destroyed, only transformed. Discover how the universe's energy stays constant and how q, w, and delta e apply.