7. Why ceramic materials are, in general, harder yet more brittle than metals. A. Ceramic materials are mainly covalent bonding than metals B. Ceramic materials have fewer defects than metals C. Ceramic materials have fewer slip system than metals D. Ceramic materials have more impurities than metals E. Ceramic materials have more unique crystal structures than metals 8. A three-point bending test was performed on an aluminum oxide specimen having a circular cross section of radius 5.0mm; the specimen fractured at a load of 3000N when the distance between the support points was 40mm. Another test is to be performed on a specimen of this same material, but one that has a square cross section of 15mm length on each edge. At what load would you expect this specimen to fracture if the support point separation is maintained at 40mm