Covalent bonds

Secondary bonds

Ionic bonds

Metallic bonds

Elastic and plastic deformation are mutually exclusive; only one of them can occur at a given moment

Plastic deformation occurs in various different types of material, not just plastics

Elastic deformation is recoverable because none of the bonds within the material are broken

Plastic deformation occurs when bonds in a material are broken

Elastic modulus is dependent on the types of bonds that are present in a material, as well as other factors

UTS  < Yield stress < 0.2% proof stress

0.2% proof stress < UTS < Yield stress

UTS < 0.2% proof stress < Yield stress

Yield stress < UTS < 0.2% proof stress

Yield stress < 0.2% proof stress < UTS

0.2% proof stress < Yield stress < UTS

Because the fracture strain does not take into account work hardening.

Because the fracture strain is a measure of engineering or nominal strain, not true strain.

Because the fracture strain is only measured at fracture.

Because the fracture strain cannot be measured accurately during a test.

Because the fracture strain is the sum of elastic and plastic strain.