The pH scale shows:
- A measurement of 7 is neutral
- Measurements below 7 are labeled ‘Increasingly acidic’
- Measurements above 7 are labeled ‘Increasingly basic’
Materials in increasing order of acidity are: Milk, normal rainfall, acid rain, tomato juice, lemon juice, stomach acid.
Neutral materials: Pure water.
Increasing basic materials are: Human blood, seawater, toothpaste, soap, ammonia solution, bleach, and oven cleaner.