In the initial linear section of the stress-strain curve of a metal or alloy. Explain from the point of view of atomic structure?(a) No, the atomic level properties of the material can never be related to the linear section.(b) The elastic zone is influenced by the strength of the bonds between atoms.(c) The stronger the bond, the less rigid and the lower the Young's Modulus of the material tested.(d) The stronger the bond, the less stress is necessary to apply to the material to deform it elastically.

The degree of polymerization of polytetrafluoroethylene (Teflon) is 7500 (mers/mol). If all polymer chains have equal length, state the molecular weight of the polymer and the total number of chains in 1000 g of the polymer(a) 50 000 g/mol; 0.03·1020 chains(b) 100 000 g/mol; 1.03·1020 chains(c) 750 000 g/mol; 8.03·1020 chains

In natural rubber or polyisoprene, the trans isomer leads to a higher degree of crystallinity and density than the cis isomer of the same polymer, because(a) it is more symmetrical and regular.(b) it is less symmetrical.(c) it is irregular.