Protons, neutrons and electrons, isotopes and relative atomic mass, electron configuration, and how the periodic table encodes all of it.
4 free units in this chapter
Atoms are built from three particles, and their arrangement explains every chemical property.
About 3 minAtoms of the same element can differ in neutron count, which explains non-whole-number atomic masses.
About 3 minElectrons occupy energy levels in a set order, and the outer electrons determine bonding.
About 3 minThe periodic table organises elements so that properties repeat predictably.
About 3 min