Chemical Bonding, Substances, and Material Properties

Comprehensive vocabulary flashcards covering ionic, metallic, and molecular substances, along with carbon allotropes, polymers, and their key structural properties.

Ionic compound

A substance made of positive and negative ions arranged in a repeating lattice.

Ionic bond

The electrostatic attraction between oppositely charged ions.

Ionic lattice

A repeating three-dimensional arrangement of positive and negative ions.

Solubility

The ability of a substance to dissolve in a solvent.

Solute

The substance that dissolves in a solvent.

Solvent

The substance that dissolves a solute.

Conductivity

The ability of a substance to conduct electricity or heat.

Brittleness

The tendency of a material to crack or break when force is applied.

Melting point

The temperature at which a solid changes into a liquid.

Boiling point

The temperature at which a liquid changes into a gas.

High melting points of ionic substances

Strong attractions between oppositely charged ions require lots of energy to overcome.

Electrical conductivity of ionic substances

Ionic substances conduct electricity when molten or dissolved in water because their ions can move freely; in solid form, they do not conduct because their ions are fixed in place.

Brittleness of ionic substances (mechanism)

When layers shift, like charges line up and repel, causing the crystal to break.

Metal

An element that typically conducts heat and electricity and can be shaped without breaking.

Metallic bonding

The electrostatic attraction between positive metal ions and delocalised electrons.

Delocalised electrons

Electrons that can move freely throughout a metal structure.

Alloy

A mixture of a metal with one or more other elements.

Corrosion

The gradual breakdown of a material through chemical reactions with its environment.

Rusting

The corrosion of iron when it reacts with oxygen and water.

Malleability

The ability of a material to be hammered or pressed into shape without breaking.

Ductility

The ability of a material to be drawn into wires.

Electrical conductivity in metals

Delocalised electrons can move and carry electrical charge throughout the metal structure.

Malleability of metals (mechanism)

Layers of metal ions can slide past each other while metallic bonding remains.

Hardness of alloys

Different-sized atoms disrupt the regular layers of atoms, making them harder to slide past each other.

Molecule

Two or more atoms joined together by covalent bonds.

Molecular substance

A substance made of separate molecules.

Covalent bond

A strong bond formed when atoms share pairs of electrons.

Intermolecular forces

Attractions between separate molecules.

Intramolecular bond

A bond holding atoms together within a molecule.

Polar molecule

A molecule with an uneven distribution of electrical charge.

Non-polar molecule

A molecule without an overall separation of positive and negative charge.

Macromolecule

A very large molecule containing many atoms.

Polymer

A large molecule made from many repeating smaller units called monomers.

Monomer

A small molecule that joins with other monomers to form a polymer.

Allotrope

A different structural form of the same element, such as diamond and graphite.

Melting and boiling points of simple molecular substances

Simple molecular substances usually have low melting and boiling points because only the weak intermolecular forces between molecules need to be overcome.

Intermolecular forces and molecular size

As molecules get larger, intermolecular forces generally become stronger, causing boiling points to increase.

Electrical conductivity of simple molecular substances

Most simple molecular substances do not conduct electricity because they do not have freely moving charged particles.

Electrical conductivity of graphite

Graphite conducts electricity because it has delocalised electrons that can move through its layers.

Hardness of diamond

Diamond is hard because each carbon atom is strongly covalently bonded to four other carbon atoms in a three-dimensional network.

Covalent bond vs. intermolecular force

Covalent bonds hold atoms together within molecules, whereas intermolecular forces attract separate molecules.

Carbon

An element that can form four covalent bonds, including bonds with other carbon atoms.

Diamond

An allotrope of carbon where each carbon atom bonds to four others in a strong three-dimensional structure.

Graphite

An allotrope of carbon made of layers of carbon atoms that can conduct electricity.

Graphene

A single layer of carbon atoms arranged in a hexagonal pattern.

Solubility of polymers

How well a polymer dissolves in a solvent, which depends on the polymer's structure and the solvent.