Untitled Flashcards Set

Ionic Bonding

Found in compounds composed of metallic and nonmetallic elements; involves atoms at the extremes of the periodic table.

Covalent Bonding

Found in materials with small differences in electronegativity (near each other in the periodic table); atoms achieve stable electron configurations by sharing electrons.

Metallic Bonding

Found in metals and their alloys; valence electrons are delocalized, forming a 'sea of electrons'.

Van der Waals Forces

Weak electric forces that attract neutral molecules, present in gases, liquefied/solidified gases, and most organic liquids/solids.

Crystalline Structure

The ordered arrangement of atoms, molecules, or ions in a solid; characterized by repeating units called unit cells.

Atomic Packing Factor (APF)

A measure of how efficiently atoms are packed within a unit cell, defined as the ratio of the total volume of atoms in a unit cell to the volume of the unit cell.

Face Centered Cubic (FCC)

Atoms located at each of the 8 corners and the centers of each of the 6 faces; atomic packing factor of 0.74.

Body Centered Cubic (BCC)

Atoms located at each of the 8 corners and the center of the cubic cell; less dense than FCC with an atomic packing factor of 0.68.

Hexagonal Close Packing (HCP)

BA packing arrangement composed of two hexagons of 6 atoms each and additional atoms in between; has an atomic packing factor of 0.74.

Simple Cubic (SC)

The simplest atomic arrangement, only containing atoms at each corner of the unit cell; least dense with an atomic packing factor of 0.52.

Point Defects

Localized disruptions in crystalline materials, which include vacancies, interstitials, impurities, and Frenkel and Schottky defects.

Elastic Modulus

A measure of a material’s stiffness, reflecting its resistance to elastic deformation under stress.

Fracture Toughness

A measure of a material's ability to resist crack propagation and indicates greater energy absorption before fracturing.

Thermal Expansion

The increase in size or volume of a material as its temperature rises; crucial for materials that undergo temperature changes.

Dielectric Properties

The ability of a material to store electrical energy in an electric field, characterized by dielectric constant and dielectric loss.

Hydroplasticity

The property of clay that allows it to become plastic and pliable when mixed with water.

Refractory Ceramics

Materials designed to withstand high temperatures without melting or decomposing, used for thermal insulation in severe environments.

Abrasive Ceramics

Materials used for wearing, grinding, or cutting softer materials, requiring properties like hardness and wear resistance.

X-Ray Diffraction

A technique used to study the atomic structure of materials by analyzing the pattern of scattered X-rays.

TTT Diagrams

Charts that show the phase transformations of materials at different temperatures and times.

Thermal Shock

The stress and potential cracking of a material undergoing rapid temperature changes.

Non-Centrosymmetric Crystals

Structures required to exhibit piezoelectricity, allowing them to generate electric charge under mechanical stress.