Define modulus of elasticity, stiffness, brittleness, and ductility

What will be an ideal response?

ANS: The modulus of elasticity is the ratio of stress to strain at any point in the stress-strain curve. A
large applied load that results in only a small deformation will have a high modulus of elasticity.
The steeper the stress-strain curve, the higher is the modulus of elasticity. Because the material
does not readily respond to an applied load, it is considered stiff (therefore, stiffness is equivalent
to the modulus of elasticity). A tissue is brittle when the plastic region is very small or
absentâ€"that is, the material undergoes very little deformation prior to ultimate failure. A ductile
material, in contrast, can undergo considerable deformation prior to failure.