Answer:
yes. they can block the wind which causes top soil erosion and they also soak up some the water in the soil
Answer:
Procedure (2)
Explanation:
Assume the dialyses come to equilibrium in the allotted times.
Procedure (1)
If you are dialyzing 5 mL of sample against 4 L of water, the concentration of NaCl will be decreased by a factor of
![\dfrac{5}{4000} = \dfrac{1}{800}](https://tex.z-dn.net/?f=%5Cdfrac%7B5%7D%7B4000%7D%20%3D%20%5Cdfrac%7B1%7D%7B800%7D)
Procedure (2)
For the first dialysis, the factor is
![\dfrac{5}{1000} = \dfrac{1}{200}](https://tex.z-dn.net/?f=%5Cdfrac%7B5%7D%7B1000%7D%20%3D%20%5Cdfrac%7B1%7D%7B200%7D)
After a second dialysis, the original concentration of NaCl will be reduced by a factor of
![\dfrac{1}{200} \times \dfrac{1}{200} = \dfrac{1}{40000}](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B200%7D%20%5Ctimes%20%5Cdfrac%7B1%7D%7B200%7D%20%3D%20%5Cdfrac%7B1%7D%7B40000%7D)
Procedure (2) is more efficient by a factor of
![\dfrac{40000}{800} = \mathbf{50}](https://tex.z-dn.net/?f=%5Cdfrac%7B40000%7D%7B800%7D%20%3D%20%5Cmathbf%7B50%7D)
Answer: If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.
Explanation: