Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
3 courses
Formulas and Stoichiometry
Chemistry · High School (11–12) · Stoichiometry and Concentration, The Mole Concept, Molecules, Ions and Formulae
FreeCh 1 · 3/4
Find a compound's formula from its percentage composition, work out how much of each substance a reaction needs and makes, find the limiting reagent, and express the strength of a solution.
3Lessons12Problems2Python Labs1Question Set1Mock Test
Laws, Atoms and the Mole
Chemistry · High School (11–12) · Laws of Chemical Combination, The Mole Concept, Molecules, Ions and Formulae
FreeCh 1 · 2/4
Five laws of chemical combination led Dalton to the atom. Use them, find atomic and molecular masses, and meet the mole: the chemist's way of counting particles by weighing them.
3Lessons11Problems2Python Labs1Question Set1Mock Test
Molecular Mass and the Mole
Chemistry · High School (9–10), General · The Mole Concept
FreeCh 3 · 3/4
A chemist cannot count atoms one by one, because there are too many of them. In this course we find the mass of a molecule, and we learn the mole, which lets us count a very large number of particles by weighing.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Atoms and Molecules: Advanced Problem Workshop
Chemistry · High School (9–10) · The Mole Concept
StandardFirst lesson freeExtra course
How many atoms are in a gram of carbon dioxide? Why do of hydrogen and of oxygen hold exactly the same number of atoms? How long would it take to count the molecules in one drop of water? In this workshop you learn two strategies, and then you solve problems that are a step harder than the chapter, with Python to check your work.
3Lessons9Problems2Python Labs1Question Set1Mock Test
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