Chemistry Learning Path
High School (11–12) Chemistry
Explore structured chemistry courses, solved problems, simulations and Python activities.
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Molecular Orbitals and Hydrogen Bonding
StemPy LabHow atomic orbitals combine into bonding and antibonding molecular orbitals, the energy order for second-period molecules, bond order and magnetism, and the hydrogen bond.
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Shapes of Molecules
VSEPR theory and the shapes it predicts, with lone pairs that squeeze the angles; valence bond theory, sigma and pi bonds; and hybridisation from sp to sp3d2.
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Ionic and Covalent Bonds
The octet rule and Lewis structures, formal charge and its limits, the ionic bond and lattice enthalpy, and the bond length, angle, enthalpy and order that describe any bond.
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Periodic Trends in Properties
How the size of atoms and ions, the ionisation enthalpy, the electron gain enthalpy and the electronegativity change across a period and down a group, and how they decide valence and reactivity.
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Building the Periodic Table
From Dobereiner's triads to Mendeleev's gaps and Moseley's atomic numbers: how the periodic table was built, how new elements are named, and how the s, p, d and f blocks follow from electron configurations.
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Formulas and Stoichiometry
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.
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Laws, Atoms and the Mole
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.
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Matter and Measurement
Sort matter into elements, compounds and mixtures, and measure it in SI units. Learn to write numbers in scientific notation, to keep the right significant figures, and to change units without mistakes.
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The Quantum Model and Electron Configurations
Bohr's circles work for hydrogen, and they fail for every other atom. The better picture is a cloud of probability. In this course we meet the waves of matter, the uncertainty principle, the four quantum numbers and the shapes of orbitals. Then we use three rules to write the electron configuration of any atom, and we explain the odd cases, such as chromium and copper.
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Light, Spectra and the Bohr Model
Heat an element in a flame, and it gives out its own colours. Hydrogen gives a few sharp lines, and not a smooth rainbow. In this course we learn how light behaves as a wave and as a stream of particles, how the lines of hydrogen are counted, and how Bohr explained them with energy levels, with numbers that you can check.
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The Nuclear Atom: Particles, Nucleus and Isotopes
How do you weigh something that no one has ever seen? Thomson, Millikan and Rutherford did it with glowing tubes, oil drops and a thin gold foil. In this course we see how the electron, the proton and the neutron were found, how big the nucleus is, and how a mass spectrometer finds the isotopes of an element.
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