Answer:
1000 times.
Explanation:
Hello,
In this case, since the pH is defined by:
![pH=-log([H^+])](https://tex.z-dn.net/?f=pH%3D-log%28%5BH%5E%2B%5D%29)
If we want to compute the concentration of hydrogen we must write:
![[H^+]=10^{-pH}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-pH%7D)
Thus, for both the backyard soils we compute:
![[H^+]_{pH=7}=10^{-7}=1x10^{-7}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D_%7BpH%3D7%7D%3D10%5E%7B-7%7D%3D1x10%5E%7B-7%7DM)
![[H^+]_{pH=4}=10^{-4}=1x10^{-4}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D_%7BpH%3D4%7D%3D10%5E%7B-4%7D%3D1x10%5E%7B-4%7DM)
It means that:
![\frac{[H^+]_{pH=4}}{[H^+]_{pH=7}} =\frac{1x10^{-4}M}{1x10^{-7}M}\\ \\\frac{[H^+]_{pH=4}}{[H^+]_{pH=7}}=1000](https://tex.z-dn.net/?f=%5Cfrac%7B%5BH%5E%2B%5D_%7BpH%3D4%7D%7D%7B%5BH%5E%2B%5D_%7BpH%3D7%7D%7D%20%3D%5Cfrac%7B1x10%5E%7B-4%7DM%7D%7B1x10%5E%7B-7%7DM%7D%5C%5C%20%5C%5C%5Cfrac%7B%5BH%5E%2B%5D_%7BpH%3D4%7D%7D%7B%5BH%5E%2B%5D_%7BpH%3D7%7D%7D%3D1000)
It means that the concentration of hydrogen at a pH of 4 is 1000 times greater than the concentration of hydrogen at a pH of 7.
Regards.
Feel free to ask if you still don't understand
The Cambrian Period marks an important point in the history of life on Earth; it is the time when most of the major groups of animals first appear in the fossil record. This event is sometimes called the "Cambrian Explosion," because of the relatively short time over which this diversity of forms appears
both sudden slip on a fault
The best answer in this case is C, "the researchers applied creativity to solve a problem in running an experiment".
Distributing the computing load across the global community by sharing processing power is a creative response to tackle the challenge in simulating protein folding for the experiment. This does not change or reduce the scientific merits of the experiment, so we can discount the first two answers (a & b). Answer d talks about well established scientific techniques, although the question wasn't really centered around the specific techniques, so it's not as relevant an answer as C.