A different model for how air becomes ionized in a spark focuses on energy. Suppose that a very energetic particle collided
with a nitrogen or oxygen atom and knocked out an electron, ionizing the molecule. Estimate the kinetic energy required for
this process.
(a) Consider an outer electron in a nitrogen atom, interacting with the atomic core (nucleus plus all other electrons).
What is the net charge of the atomic core?
(b) Assuming the radius of the nitrogen atom is about , what is the electric potential at the location of this
outer electron?
(c) Ionizing the atom means moving the outer electron a very large distance away from the atomic core. What is the
electric potential a very large distance from the atomic core?
(d) What is the potential difference between these two locations?
(e) What is the change in electric potential energy of the system of the electron plus the atomic core in this process?
(f) How much kinetic energy would an incoming particle need in order to ionize the atom in a collision between the
particle and the atom?