Recent data allow a new parametrization of the neutron charge form factor G n E . A parameter-free quark-model relation between G n E and the N →∆ quadrupole form factor G N→∆
C2is used to predict G N→∆ C2 from G n E data. In particular, < r 2 n > is related to N →∆ quadrupole moment QN→∆, while < r 4 n > connects to the N →∆ quadrupole transition radius < r 2 N→∆ >. From the latter we derive an experimental value for the charge radius of the light constituent quarks rγq = 0.8 fm. Finally, the C2/M1 ratio in pion electroproduction is predicted from the elastic neutron form factor data.Intrinsic nucleon structure -The nucleon is a complicated many-particle system composed of valence quarks, which carry the quantum numbers, and nonvalence quark degrees of freedom, which describe the cloud of quark-antiquark (qq) pairs and gluons. The constituent quark model (CQM) with two-body exchange currents describes both these aspects of nucleon structure [1]. One-body currents describe the interaction of the photon with one valence quark at a time. Two-body exchange currents are connected with the exchange particles (gluons, pions) and with qq pairs (see Fig. 1(b-d)). Nucleon properties which are dominated by two-body exchange currents show their common dynamical origin in analytical interrelations.In this paper, a quark model relation between the neutron charge form factor G n E and the quadrupole transition form factor G N →∆
C2is used together with a parametrization of new G n E data to predict G N →∆
C2and the C2/M1 ratio usually measured by pion electroproduction. The spin-isospin dependence of the two-body charge operator ρ [2] , e.g. for the gluon, can be written schematically aswhere q is the three-momentum transfer, e i and σ i the quark charge and spin. Explicit expressions can be found in Ref.[1]. As a result of (i) the dominance of ρ [2] [1,2] and of (ii) the spin-isospin structure in ρ [2] and in the N and ∆ wave functions, a connection between the neutron charge form factor G n E (q 2 ) and the N →∆ quadrupole transition form factor G N →∆
C2(q 2 ) emerges [3] as follows:The derivation is independent of the spatial part of the quark wave functions and holds irrespective of whether gluon or pion exchange or both are employed. One-body contributions to G n E and G N →∆
C2arise only through excited-state admixtures which amount to less than 20% of the empirical values if a quark core radius consistent with the excitation spectrum [2,4] is used. Three-body corrections are estimated to contribute less than 30% of the two-body currents using a QCD parametrization [5] and a large 1/N c approach [6]. These approaches also show the dominance of the two-body exchange currents for both observables.The dominance of nonvalence quark degrees of freedom in G n E and G N →∆
C2is not specific to this quark model. Also chiral approaches, e.g. the Skyrme model [7], the σ-model [8], the Nambu-Jona-Lasinio model [9], and the chiral 1