Why is possible to change instantaneously voltage across a resistor?
The capacitor and inductor do not allow sudden changes in voltage or current.
This is because both devices build up fields in themselves (electrical in the capacitor and magnetic in the inductor), which contributes to the inertia behavior of the device.
The capacitor and inductance do not allow sudden changes in voltage or current.
Indeed, the two devices create fields in themselves (electrical in the capacitor and magnetic in the inductance), which contributes to the inertial behavior of the device.
These fields are created according to their physical structure in the devices.
Consequently, the devices only react when the excitation time exceeds the time necessary to cancel the energy generated by the fields. None of these phenomena exists in resistance.
The resistors have only obstacles in the path of the charge flow, because of which heat is generated (energy dissipation).
Therefore, resistance is not a capacitor or inductor when it comes to resisting sudden changes in voltage and current. The above explanation applies taking into account the ideal devices.
Why is it possible to change the voltage across a resistor immediately?
Because it’s a resistor and not a capacitor or inductor. At least this is the answer when it comes to ideal components.
In reality there are no perfectly resistive components, just as there are no purely capacitive or inductive components.
For example, if you work with “power resistors”, usually wire-wound devices, and you want to use them at moderately high frequencies, you need to specify non-inductive windings.
A standard specified parameter of a capacitor is ESR or an equivalent series resistor.