Kαλημέρα! What's left of the dwindling Greek community in Chicago sends its regards.
The nature of your question really generalizes to a good philosophical question. How is an empirical explanation like that of electrostatics not deductive?
The short answer is, it is to an extent. However, it is not primarily a deductive activity. There are many ways science is done ranging from the methods used by particle physicists to those of ecological biologists to those methods of social scientists like economists. Each has a related, but different philosophical method, different tools, literally and metaphorically, and different matters of study that lend themselves to discovery and explanation in different ways. While science may replace branches of philosophy, philosophy attacks problems in ways no science can.
Even among a hard science, like physics, there are differences such as those among particle physics, cosmology, and materials science. This range of scientific methods is infamous as the philosophical problem of the demarcation of science which I believe stems more from adhering to the notion that classical sets are better tools for classification than fuzzy sets. There are deep divides in philosophical positions based on metaphysical presumptions such as one's valuation of the value of keeping an eye on Wittgenstein's notion of family resemblance or adhering to the law of the excluded middle in one's logics. Tempted as I am to perch on my soapbox, let's move forward.
You probably know, it is likely the English word 'electron' has an etymology ultimately derived from the ancient Greek 'amber'. Did Thales of Miletus, Heraclitus of Ephesus, or Galen of Pergamum use deduction when exploring the natural world? Yes! How about Galileo Galilei, Rene Descartes, or James Clark Maxwell use deduction? Even more so with the mathematization of science, surely. But, explanations do not conform well to purely deductive models, most famously, the Hempelian deductive-nomological model. To clear up your misunderstanding, you need to get to the current understanding of explanation within the philosophy of science.
I recommend Blackwell's Companion to the Philosophy of Science. though I think Routledge may have one. There are others, but it's easier than working through SEP or the Encyclopedia of Philosophy. On page 127, W. H. Newton-Smith says:
Very few explanations actually encountered in everyday life or in science have [a deductively] precise form.... we sketch part of a story which we are betting could be elaborated so as to incorporate appropriate laws, given further empirical [emphasis mine] research.
Indeed, unlike mathematics which is primarily viewed as a deductive activity like as Euclid's geometry, science is much more in the spirit of trial and error, and has a strong component of engineering which proceeds from watching prototypes fail. Like logic, math is generally limited inadequately describing the world, and whole theories of math deal with uncertainty such as statistics, stochastics, and chaos theory. The very ontological nature of the electron itself is mathematically uncertain. Even Newton's vaunted laws of gravitation become almost useless when a third body is added to a dynamic situation.
Deductive logic and math play a role in electrostatics, certainly, but there are other forms of explanation. Another aspect of electrostatic explanation can be viewed in terms of causality, which is a philosophical problem in and of itself. Some scientists go so far as to reject it completely preferring to see all systems as possessing latent variables which undermine deterministic certainty. Math, after all, is a model of the universe, not the universe itself (despite the recent fad of considering the universe a simulation without empirical evidence).
So, in terms of causality, particles are unpredictable and not subject entirely to deductive logic. This is why the causal-relevance model of explanation offers a complementary tool for dealing with understanding electrostatics. In the C-R model of phenomena, they are understood in terms of causally relevant features which aren't arrived at through a priori reasoning but from a posteriori experience, which is the heart of the empirical tradition. Modern chemistry started off as two distinct types of alchemy, those of living substance and those of non-living substance. Through experiment, chemists eventually rebutted the logical conclusion that living substances were animated with an elan vital leading to the abandonment of vitalism. An understanding of electrons has always been facilitated by deductive reason, but far more inductive and empirical methods. This is why abductive logic is generally seen as the primary way we form explanations about phenomena. Human logic is largely defeasible. Intellectuals have tended towards certainty in methods, but the universe and the mind are largely non-deterministic.
In fact, other models besides the D-N and C-R models of scientific explanation abound. Again, according to Newton-Smith on page 130:
We have an embarrassment of riches. We have explanations by reference to causation, to identities, to analogies, to unification, and possibly other factors. Philosophically we would like to find some deeper theory that explained what it was about each of these... forms... that makes them explanatory.
So to conclude, electrostatics can be seen as partially deductive, but there are more important characteristics of the theory including abstracting causal models, inductive thinking, and defeasible reasoning based on experimentation. Science is not the axiomatic method of reasoning but requires experimental apparatuses and debates.