Form factor is a hardware design aspect that defines and prescribes the size, shape, and other physical specifications of components, particularly in electronics.[1][2] A form factor may represent a broad class of similarly sized components, or it may prescribe a specific standard.
Form factor is commonly used to describe the design, size and/or arrangement of a device, a computer case or chassis, or one of the device's internal components, such as a motherboard or a daughterboard.

Form Factor of the Nuclei. Electron scattering with a nucleus with a charge distribution.The Form Factor of Isotopes is sligthly different since the neutron rich nuclei present the minima for smaller q values. Indeed for equal number of protons the nuclear volume becomes bigger.

As we can see from the illustration, Electronic Form Factor Change has many fascinating aspects to explore.