Concept Map

The textbook's concept map ties the whole unit together under the single title "Atom," branching into two broad halves. One branch runs through the historical progression of atomic models - built up from the discovery of sub-atomic particles (electron, proton, neutron) through J.J. Thomson's model, Rutherford's model, and finally the quantum mechanical model - and is separately fed by the dual nature of matter, itself branching into the de Broglie concept and Heisenberg's uncertainty principle. The other branch runs from the Schrödinger wave equation, $\hat{H}\psi=E\psi$, to its solution - the wavefunction $\psi$ and its eigen-values - which in turn produces atomic orbitals. From atomic orbitals, three further branches fan out: quantum numbers (principal $n$, azimuthal $l$, magnetic $m$, spin $s$), the shapes of atomic orbitals (splitting into radial distribution and angular distribution, giving the spherical s-orbital, dumbbell p-orbital and clover-leaf d-orbital shapes, all governed by $\psi^2$, the probability of finding the electron), and the filling of electrons in atomic orbitals (governed by the Aufbau principle, Pauli's exclusion principle and Hund's rule), which itself leads on to the **stability of half-filled and fully-filled …