Bonding and Structures Lecture Notes

Vocabulary flashcards covering ionic, covalent, metallic bonding, giant lattices, polymers, allotropes of carbon, and related properties.

Ionic Compound

A substance formed from metal and non-metal ions held together by strong electrostatic forces of attraction in all directions.

Giant Ionic Lattice

Three-dimensional arrangement of oppositely charged ions in an ionic compound responsible for high melting and boiling points.

Electrostatic Forces of Attraction

Strong forces between positive and negative ions; large amounts of energy are required to overcome them.

Brittleness (Ionic Solids)

Property of ionic crystals that crack when like-charged ions are forced next to each other, causing repulsion.

Electrical Conductivity of Ionic Solids

Ionic solids do not conduct because their ions are fixed and no free charges can move.

Electrical Conductivity of Ionic Liquids/Solutions

Molten or dissolved ionic compounds conduct electricity because ions are free to move and carry charge.

Solubility of Ionic Compounds

Usually dissolve in water because water’s positive and negative ends attract the ions.

Covalent Bond

A shared pair of electrons between two non-metal atoms.

Simple Covalent Molecule

Small molecule with few atoms joined by covalent bonds and weak intermolecular forces, e.g., Cl₂, N₂, CO₂, NH₃.

Intermolecular Forces

Weak attractions between molecules; give simple covalent substances low melting and boiling points.

Polymer

Large molecule made of repeating smaller units (monomers) joined by covalent bonds.

Monomer

A small molecule that chemically bonds to identical units to form a polymer.

Polymerisation

The chemical process in which monomers join together to form a polymer chain.

Giant Covalent Structure

A vast network of atoms connected by strong covalent bonds, giving very high melting points and hardness.

Diamond

Allotrope of carbon where each atom forms four covalent bonds; very hard, high melting point, electrical insulator.

Graphite

Allotrope of carbon with layers of hexagonally arranged atoms; three covalent bonds per atom, delocalised electrons conduct electricity, layers slide making it a lubricant.

Silicon Dioxide (SiO₂)

Giant covalent compound where each silicon bonds to four oxygens; high melting point and an electrical insulator.

Graphene

Single one-atom-thick sheet of graphite; strong covalent bonds, excellent electrical conductor due to delocalised electrons.

Fullerene

Molecule of carbon atoms arranged in hexagons (and pentagons); can form hollow cages to deliver drugs and act as catalysts.

Carbon Nanotube

Cylindrical fullerene with high tensile strength and good thermal and electrical conductivity.

Metallic Bonding

Attraction between positive metal ions and a sea of delocalised electrons in a giant metallic lattice.

Delocalised Electrons (Metals)

Free electrons in metals that move through the lattice, allowing electrical and thermal conductivity.

Malleability of Metals

Layers of metal ions can slide over each other, enabling metals to be hammered or rolled into shapes.

Alloy

Mixture of a metal with other elements; differing atom sizes disrupt layers, making the material harder than pure metal.

High Tensile Strength

Resistance of a material (e.g., nanotubes) to breaking under stretching forces.