Understanding acids and bases is important because they show up in many everyday situations.

1. Basic Definitions:

   • Arrhenius Definition: Acids create $H^+$ ions, and bases create $OH^-$ ions when they're mixed with water.
   • Brønsted-Lowry Definition: Acids give away protons, while bases take in protons.

2. How They Work in Real Life:

   • pH Scale: This scale goes from 0 to 14. If something has a pH under 7, it's acidic. If it's above 7, it's basic. Each time you move one number on the scale, it changes acidity or basicity by ten times!
   • Natural pH Levels: Most drinking water has a pH between 6.5 and 8.5. This range is important for our health.

3. Important Facts:

   • Household Items: Up to 70% of cleaning supplies you see in stores are either acidic or basic.
   • Health: Human blood usually has a pH of about 7.4. This balance is vital because if it changes too much, it can cause serious health problems.

Knowing these definitions helps us use this information in everyday life, whether we're cooking or studying the environment.