Midterm Exam Questions

1) Massive clay only has small (micro) pores, while sand only has large (macro) pores. Consequently, large pores in sand louse water very quickly (as indicated by a prominent drop in its water retention curve)with the deceasing matric potential. On the other hand, small proes of the massive clay, hold tightly on the water molecules and there is very little change in water content with a decreasing matric potential (as shown by its almost flat curve)

2)Soil colloids are small and as such they have large specific surface area and in addition they usually have lots of charges on their surfaces.