Which of the following is implied by a small screening length aTF? The electron screening effect becomes significant at small ion-atom separation r. The magnitude of the screened potential V decreases quickly to zero at small values of x The magnitude of the screened potential V decreases slowly to zero at large values of x The electron screening effect becomes significant at large ion-atom separation r. The approaching ion will begin to undergo an interaction with the atom at only when it is close to the atomic nucleus (i.e. only at small r) O The approaching ion will begin to undergo an interaction with the atom at large distance from the atomic nucleus (i.e. at large r)