Hydrogen ions, often represented as H⁺, are positively charged particles that form when a hydrogen atom loses its electron. This process occurs in various chemical reactions, particularly in acids, where the release of H⁺ ions contributes to the acidic properties of a solution. In aqueous solutions, the concentration of H⁺ ions is crucial for determining the pH level, which measures how acidic or basic a solution is. A higher concentration of H⁺ ions corresponds to a lower pH, indicating a more acidic environment, while a lower concentration results in a higher pH, signifying a more basic solution.