We are given pH values 3, 12, 2, 7, or 9.
We know that on the pH scale, 7 is neutral, less than 7 are acidic and greater than 7 are basic (alkaline).
As we go from greater to less numbers than 7, it becomes more and more acidic.
And if we go from greater and greater number than 7, it becomes more basic.
Now, we can conclude the given numbers and their nature on pH scale.
7 is neutral, 3 is acidic and 2 is stronger acidic than 3.
9 is basic and 12 is stronger basic than 9.
