Answer:
The pH scale measures acidity of a substance. known as potential of hydrogen, it varies from 0 to 14 with 7 being the pH value of a neutral solution. Below 7 shows the substance is acidic in nature and above 7 is alkaline in nature. pH 0-3 are considered strong acids while pH 4-6 are weak acids. pH 8-10 are weak alkalines and pH 11-14 are strong alkalines. This is a general trend and there may be exeptions especially if the substance has a negative pH. However, it would not be covered likely unless you are doing university chemistry.