  A symmetry-preserving truncation of the quantum field equations describing
hadron properties is used to deliver parameter-free predictions for all nucleon
elastic electromagnetic form factors and their flavour separation to large
values of momentum transfer, $Q^2$. The proton electric form factor, $G_E^p$,
possesses a zero, whereas that of the neutron, $G_E^n$, does not. The
difference owes to the behaviour of the Pauli form factor of the proton's
singly-represented valence $d$-quark. Consequently, $G_E^n>G_E^p$ on a material
large-$Q^2$ domain. These predictions can be tested in modern experiments.
