Explanation:
Relation between pH and concentration of hydrogen ions is as follows.
pH = ![-log [H^{+}]](https://tex.z-dn.net/?f=-log%20%5BH%5E%7B%2B%7D%5D)
So, it means that an increase in the value of pH will show that there occurs a decrease in concentration of hydrogen ions.
Therefore, the solution becomes basic in nature.
On the other hand, a decrease in the value of pH will show that there occurs an increase in the concentration of hydrogen ions.
Therefore, the solution becomes more acidic in nature.
Hence, if the pH of a solution is decreased from pH 8 to pH 6 it means that the concentration of hydrogen ions has increased in the solution.
The answer would be 2.0 x 10^-1
Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.
Look at the liter man it’s a great way to learn how much every liquid measurement is