Final answer:
Brazil became an independent nation not when Dom João made his son Pedro emperor, but when Pedro I declared independence from Portugal on September 7, 1822, following his father's return to Portugal and conflicts with the Portuguese Cortes. Pedro I declared independence and was later crowned emperor, continuing a monarchy under a new constitutional framework. The statement in the question is false.
Step-by-step explanation:
The statement that Brazil became an independent nation when Dom João made his son Pedro emperor is false. Instead, Brazil's path to independence happened after Dom João, who had been ruling from Brazil, returned to Portugal in 1821 and left his son, Dom Pedro I, as prince regent. Disagreements with the Portuguese Cortes led Pedro I to side with the Brazilian elites who preferred independence over the recolonization efforts of the Cortes.
On September 7, 1822, following escalating tensions, Pedro I declared Brazilian independence by the banks of the Ipiranga River, an act known as the Grito do Ipiranga (Ipiranga Cry), and he was later crowned as the Constitutional Emperor and Perpetual Defender of Brazil.
Though Brazil declared its independence under Pedro I, the social, economic, and political structures did not undergo immediate transformation. The new constitutional monarchy under Pedro I's leadership saw a continuation of the existing power dynamics, marked by the persistent influence of the Portuguese-born elite and the slavery-based agriculture economy. Ultimately, following unpopular decisions and the influence of political unrest in Europe, Pedro I abdicated in 1831 in favor of his son, Pedro II, facilitating a more definitive break from Portuguese influence and furthering Brazil's journey as an independent empire.