Which of the following statements is true regarding acids?

Acids are substances that, in an aqueous solution, release hydrogen ions (H⁺). One of the defining characteristics of acids is their effect on indicators like litmus paper. When an acid is added to blue litmus paper, it causes the paper to turn red. This property is a classic way to identify acidic substances.

The reaction occurs because the hydrogen ions produced by the acid interact with the dye in the litmus paper. This change in color indicates the presence of an acidic environment.

Other properties of acids that are worth noting include their sour taste and their ability to conduct electricity due to the presence of ions in solution. However, slippery textures and bitter tastes are associated with bases rather than acids. Understanding these fundamental properties can help in identifying and differentiating between acids and bases in various chemical contexts.