Chapter 2

Functional Classification of Materials

Classification based on the primary function they perform, such as structural materials.

Structural Materials

Materials like steels, concretes, and certain plastics that serve a structural purpose.

Crystalline Structures

Materials characterized by long-range ordering of atoms/ions/molecules in a regular pattern.

Amorphous Materials

Materials that lack long-range order, often with only short-range ordering of atoms.

Environmental Effects on Materials

Factors such as temperature, corrosion, fatigue, and strain-rate that impact material properties.

Atomic Bonds

Types of bonds including metallic, covalent, ionic, and secondary bonds that determine material properties.

Bohr Model of the Atom

A model treating atoms as a mini solar system with protons and neutrons in the nucleus and electrons in orbitals.

Atomic Number (Z)

The number of protons in the nucleus of an atom, characterizing each element.

Valence Electrons

Electrons in the outermost incomplete shell of an atom that can participate in forming bonds.

Electronegativity

A relative measure of an atom’s ability to attract electrons, significant in bond formation.

Types of Atomic Bonds

Categories of bonds such as metallic, covalent, ionic, and van der Waals bonding.

Ionic Bonding

Bonding that occurs due to the electrostatic attraction between positive and negative ions.

Covalent Bonding

Bonding characterized by the sharing of electron pairs between atoms.

Van der Waals Bonding

Weak bonding interactions that occur between molecules due to induced polarization.

Mixed Bonding

Materials exhibiting characteristics of more than one type of bonding due to differing electronegativities.

Bond Energies

The energy required to break a bond, indicative of bond strength; Ionic bonds have the highest energy.

Elastic Modulus (E)

A measure of a material's ability to deform under stress.

Coefficient of Linear Thermal Expansion (α)

A measure of how a material expands when heated.