  This is the first paper of a series aiming to present a new teaching sequence
for Particle Physics in high school. We propose a systematic discussion of the
subject, covering not only the understanding of its key concepts, but also of
the very nature of Science, of the factors that surround its practice and of
its relations to technology, society and the environment, in a framework
towards scientific literacy. In this work we present the first part of this
teaching sequence, focused on the quantum theory of electromagnetism: Quantum
Electrodynamics. We analyze the potentialities of the material proposed here,
when applied in a dialogic manner by the teacher, by evaluating the presence of
scientific literacy and engagement indicators throughout interventions at a
full-time public school in Espirito Santo, Brazil.
