All systems from atoms to asteroids, i.e. from 10-10 m to 105 m, come to equilibrium under the action of the squeezing pressure of (mainly) electrostatic forces of the form Σj∓e2/rij2 and the expansive pressure of the quantum perpetual motion associated with the Heisenberg/Pauli kinetic energy given by the formula EK ∝ ℏ2N5/3/meV2/3. Thus all physical quantities ought to depend on the universal constants ℏ, e, me or, equivalently, ℏ, e, aB≡ℏ2/me2 and possibly others. This allows extensive use of dimensional analysis coupled with a "little physical thinking" as a tool for estimating the values of physical quantities.
The size and the ionization potential of the atoms is obtained this way; to obtain the angular dependence of the atomic orbitals, which determines the structure of the periodic table of the elements, requires some simple mathematical manipulations. Dimensional analysis and a "little physical thinking" produces reasonable estimates for quantities associated with molecules, solids, and liquids with the exception of electrical conductivity; this last failure proves to be revealing in understanding the true nature of the motion of detached electrons in solids.