In an atomic system two point charges and are separated by a distance
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
In an atomic system two point charges q1 and q2 are separated by a distance r1, resulting in an initial electrostatic force of magnitude F1. The separation is then scaled to a new value r2=nr1, where n is a positive real number greater than 1.
Answer the following in symbolic form before substituting any numerical values.
(a) Derive an expression for the ratio F1F2 of the new force magnitude F2 to the original force magnitude F1 in terms of the scale factor n.
(b) Using your result from part (a), obtain a general formula for the percent change in force when the separation is multiplied by the factor n.
(c) Evaluate the percent change when n=3.00 for a proton–electron pair.
(d) Interpret physically what your calculation in part (c) implies about the stability of an electron that is promoted to a shell three times farther from the nucleus than its ground-state distance.