Lower than 7 is acid greater than 7 is a base
Answer:
See explaination
Explanation:
please kindly see attachment for the step by step solution of the given problem.
The patch area in square kilometers is 1.59*10⁻⁹ km₂
Why?
This is an unit conversion problem. We have to convert from cm² to km². We can do that by knowing that there are 100 cm in 1 m, and 1000 m in 1 km, so 100000 cm=1km. Knowing that we can apply the following conversion factor:

Now to convert this value to scientific notation, we have to move the decimal point to the right until we get a whole number, and the exponent of the number 10 is going to be the number of spaces we moved to the right (negative), so the final answer is:

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#LearnwithBrainly
<span>The balloons volume as it
rises increases because at higher altitude external pressure is lower, so the
air molecules inside the balloons tends to expand more to attain mechanical
equilibrium, where the external pressure and internal pressure are equal. Unlike
when the balloon is on the ground, external pressure is great so the gas
molecule cannot push the walls of the balloon so it is like underinflated.</span>
![pH=-\log_{10} [H_3O^+] \Rightarrow [H_3O^+]=10^{-pH} \\ \\ pH=2.8 \\ \ [H_3O^+]=10^{-2.8} \approx 1.58 \times 10^{-3}](https://tex.z-dn.net/?f=pH%3D-%5Clog_%7B10%7D%20%5BH_3O%5E%2B%5D%20%5CRightarrow%20%5BH_3O%5E%2B%5D%3D10%5E%7B-pH%7D%20%5C%5C%20%5C%5C%0ApH%3D2.8%20%5C%5C%0A%5C%20%5BH_3O%5E%2B%5D%3D10%5E%7B-2.8%7D%20%5Capprox%201.58%20%5Ctimes%2010%5E%7B-3%7D)
The [H₃O⁺] of the solution is approximately 1.58 × 10⁻³ M.