pH levels are each a 10-fold change so a change by 2 is actually a change by 1000. pH determines certain characteristics in organisms that allow them to live in certain areas so an alteration in pH changes their adaption skills.

why is a change by 2 = 1000?

what would a change by 4 = ?

pH is logarithmic

a change of 2 in pH means a hundred times change in the concentration of H+
... 10^2 = 100

10^4 = 10000

the answer in the book says a change by 2 is 1000?

is a change by 2 = 100 and the book answer is wrong.

The relationship between pH values and their corresponding concentration of hydrogen ions (H+) is logarithmic. Each unit change in pH represents a 10-fold change in H+ concentration. So, when you compare two pH values that differ by 2 units, it corresponds to a 10-fold change raised to the power of 2, which is 10 x 10 = 100. Hence, a change by 2 in pH corresponds to a change by 100.

If you want to calculate what a change by 4 in pH represents, you can use the same concept. Since each unit change in pH represents a 10-fold change in H+ concentration, a change by 4 units would correspond to a 10-fold change raised to the power of 4, which is 10 x 10 x 10 x 10 = 10,000. So, a change by 4 in pH would represent a change by 10,000.