Final answer:
The pH scale ranges from 0 to 14. Water in the human body buffers the blood and has a pH of 7.4. The stomach environment is highly acidic with a pH of 1 to 2.
Step-by-step explanation:
The pH scale ranges from 0 to 14, where anything below 7 is acidic and anything above 7 is alkaline. Water in the human body buffers the blood, making it slightly alkaline with a pH of 7.4. The environment in the stomach, on the other hand, is highly acidic with a pH of 1 to 2.