Calculate pH a decrease of one unit on the pH scale means a solution is ten times more acidic. a decrease of two units means the solution is 100 times more acidic. how much more acidic is acid precipitation( pH = 4.0) than pure water (PH= 7.0 )

Each unit of decrease has an exponential increase. So if you are looking at an item that has a Ph of 4 and water has a Ph of 7 —-that means it is 10 to the 3rd power more acidic or 1000 times more acidic than water.

Explanation:

i think the answer is a.keratin is the pigment responsible for skin color.

not always but somethings can be reproduced in a laboratory.