Answer:
Hydrogen or hydroxonium ions in the solution
Hydroxyl ions in the solution
Step-by-step explanation:
A pH of 1 shows there is a lot of hydroxonium ions in the solution and a pH of 14 shows there is a lot of hydroxyl ions in the solution. 
- The pH scale ranges from 1 to 14 
 - As the values tends towards 1, the acidity increases due to concentration of hydroxonium ions in the solution. 
 - As the pH tends towards 14, the basicity increases due to the concentration of hydrogen ions in the solution.