Why are valence electrons used in chemical bonding? A. They are free electrons that can be used by any atom.
B. They are in the nucleus of an atom.
C. They are closest to the nucleus of an atom.
D. They are in the outermost shell of an atom.

Use the profile illustrated for problem (1). assume that the layer of silty sand fill (sm) is placed over the entire site. estimate the thickness of the fill (h - in feet) that will cause the effective vertical stress at the center of the clay layer to increase by 517.5 pounds per square foot.