Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
3 courses
The Nuclear Atom: Particles, Nucleus and Isotopes
Chemistry · High School (11–12) · Subatomic Particles and Atomic Models, Isotopes and Isobars
FreeCh 2 · 1/4
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.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Isotopes and Isobars
Chemistry · High School (9–10), General · Isotopes and Isobars
FreeCh 4 · 3/3
Not all atoms of an element have the same mass, and atoms of different elements can have the same mass. In this course we learn about isotopes and isobars, why the atomic mass of chlorine is 35.5 u, and how some isotopes are used in medicine and industry.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Electron Shells, Valency and Atomic Number
Chemistry · High School (9–10), General · Electronic Configuration and Valency, Isotopes and Isobars
FreeCh 4 · 2/3
Electrons sit in shells, and the outer shell decides how an atom behaves. Here we learn the rules for filling the shells, how to find the valency of an atom, and how the atomic number and the mass number tell us the particles in an atom.
3Lessons10Problems2Python Labs1Question Set1Mock Test