What is thesource of tension in flowers for algernon?

The main source of tension in "Flowers for Algernon" is Charlie's internal struggle with his increasing intelligence and awareness, contrasted with his desire to fit in and find acceptance. As Charlie's intelligence grows, he grApples with questions about identity, relationships, and the nature of intelligence, which creates tension as he navigates these complex emotions and experiences. Additionally, there is tension in the ethical implications of the experiment and its impact on Charlie's life.