You find that the CEC of a sandy loam soil at pH 5.0 is 8 cmolc/kg and at pH 8.2 it is 14 cmolc/kg. What is the most likely reason for this difference?
A) removal of Al atoms from tetrahedral layers at low pH
B) ionization of carboxyl and phenolic groups to release H+ ions
C) removal of Al3+ ions from the exchange complex at higher pH
D) replacement of trivalent Al3+ ions with divalent Ca2+ ions at high pH
E) increase in the pH-dependent charges on 1:1 type silicate clays
B
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A ____ can be used when the ground slopes enough to provide a full wall height at the rear or side of a house.
A. solarium B. daylight basement C. day room D. divided basement
What type of fuel is made of 85% methanol and 15% petroleum?
What will be an ideal response?
Automatic parking brake releases ________
A) Use a vacuum servo B) Use an electric solenoid C) Either A or B D) Neither A nor B
A "chirping" noise is heard while the vehicle is moving forward, but stops when the brakes are applied. Technician A says that the noise is likely caused by the disc brake pad wear sensors. Technician B says the noise is likely a wheel bearing because the noise stops when the brakes are applied. Which technician is correct?
A) Technician A only B) Technician B only C) Both technicians D) Neither technician