Question

The metals with the highest values of Young’s modulus in
Figure 3.3 are also those with the highest cohesive energies and melting temperatures
(see Figure 4.16a). Are these two aspects of the same thing?

Metals Organlc other Nonmetals Fibers Graphite (Il planes) Carbon nanotubes 1000 graphene, diamond SiC SIN Carbon fibers Steel Cast iron 100 Glass fibers Carbon fibers reinforced plastic Mg NaCl Concrete Pb Graphite (L planes) Wood (Il grain) 10 Nylon Wood (L grain) Teflon PET 0.1 . Rubber Figure 3.3 Young's modulus for different materials. The values are merely a guide, as strong variations are possible.

Figure 4.16a

Answer 1

Youngs modulus is the measure of the tensile strength of a material, that is, restoring force produced in the material per unit extension
now, higher the youngs modulus, means greater will be the restoring force appearing in the material for per unit length increment due to pulling the material under tension

Now, this restoring force is due to the intermolecular or interatomic interaction of the particles of the material, and hence the cohesive forces in the material. Also, melting point is the temperaurre where these cohesive forces breakdown to change the physical state of the material from solid to liquid. Hence higher the cohesive forces, higher themelting pint ( as more energy is required to dissociate the bonds of the material) and higher the tensile strength and hence the youngs modulus of the material

hence we can say that higher youngs modulus leads to higher cohesive forces and higher melting points of materials as are aspects of the same thing