Hi , well I think that you're referring to a pure substance , in other words a substance that contains only one kind of matter.
Answer:
0
Explanation:
Since HI is a strong acid, the amoung of Hydrogen ions produced by it will be the same molar as the reactant. The negative log of the concentration will reveal that the pH is 0.
It is divided into 2 blocks one is s-block and another is p-block .
Here are first 20 known elements .