Properties of Chemicals Vocabulary Flashcards

Comprehensive vocabulary flashcards covering the key terms, bonding types, physical properties, particle models, and structural allotropes from the CB 1.4 Properties of Chemicals lecture notes.

Atom

The basic particle of chemical elements containing protons, neutrons, and electrons, with no overall charge because the number of protons equals the number of electrons.

Ion

An atom or group of atoms that has lost or gained electrons to achieve a full outer shell and stability, giving it an overall positive or negative charge.

Polyatomic Ion

An ion consisting of more than one atom joined together that carries an overall charge, such as $\text{CO}_3^{2-}$ or $\text{NH}_4^+$.

Molecule

A particle formed when two or more atoms chemically combine, carrying no overall electrical charge.

Physical Property

A feature of a material that can be observed or measured without changing its chemical composition.

Density

A measure of how much matter is contained in a fixed volume, representing how tightly packed the particles are within a given space.

Melting Point

The specific temperature at which a substance changes state from a solid into a liquid.

Boiling Point

The specific temperature at which a substance changes state from a liquid into a gas.

Temperature

A measure of the average kinetic energy of the particles within a substance.

Hardness

The ability of a solid substance to resist scratches, breaking, and deformation, determined by strong bonds holding its particles together.

Brittleness

The property of a substance that causes it to break or shatter without changing shape when an external force is applied.

Malleability

The ability of a material, particularly metals, to change shape or be hammered into thin sheets without breaking.

Ductility

The property of a material that allows it to be drawn or pulled into a thin wire shape.

Electrical Conductivity

A measure of how well a substance allows electricity to flow through it, requiring the presence of free-moving charged particles.

Thermal Conductivity

A measure of how efficiently a material transfers thermal energy (heat) through particle vibrations and collisions.

Solubility

The ability of a solute to dissolve in a given solvent, depending on the relative attractive forces between solvent molecules, solute particles, and solute-solvent interactions.

Ionic Solid

A solid consisting of a three-dimensional lattice of alternating positive metal cations and negative non-metal anions held together by strong ionic bonds.

Ionic Bond

A strong electrostatic force of attraction acting between oppositely charged ions.

Metallic Solid

A solid structured as a three-dimensional lattice of positive metal nuclei surrounded by a sea of delocalised valence electrons.

Metallic Bond

A strong, non-directional electrostatic attraction between positive metal nuclei and delocalised valence electrons.

Delocalised Electrons

Valence electrons in metallic lattices that are not bound to any single atom and can move freely throughout the structure.

Alloy

A mixture of chemical elements where the primary component is a metal, often resulting in higher strength than pure metals due to disrupted atomic arrangements.

Covalent Bond

A strong chemical bond formed when non-metal atoms overlap their outer valence shells and share electrons to attain stability.

Intermolecular Forces

Weak attractive forces that exist between discrete molecules.

Polar Molecule

A molecule with a slight charge separation across its structure, leaving one side slightly positive ($\delta+$) and the other slightly negative ($\delta-$).

Non-polar Molecule

A molecule with an even distribution of electrical charge across its entire structure.

Solute

The component of a solution that is being dissolved into a solvent.

Solvent

The substance (usually a liquid) in which a solute is dissolved to form a solution.

Solution

A homogeneous mixture formed when a solute dissolves in a solvent.

Macromolecule (Polymer)

A very large molecule composed of thousands of repeating atomic units formed by joining smaller monomer molecules together.

Monomer

A small molecular unit that chemically reacts and links with others during polymerisation to construct a polymer chain.

Polymerisation

The chemical process in which monomer units repeatedly join together to form a polymer chain.

Low Density Polyethylene (LDPE)

A polymer with significant chain branching that prevents tight packing, resulting in a lower density, more flexible material.

High Density Polyethylene (HDPE)

A polymer consisting of linear chains with few branches, allowing tight chain packing and producing a higher density, rigid material.

Cross-linking

The formation of chemical or physical bonds between adjacent polymer chains, enhancing thermal resistance, durability, and solvent resistance.

Covalent Network

A large, rigid 3D structure of non-metal atoms linked continuously by strong covalent bonds.

Allotropes

Different structural forms of the same element in the same physical state that exhibit distinct physical properties.

Diamond

An allotrope of carbon forming a 3D covalent network where each carbon atom is covalently bonded to four others in a tetrahedral arrangement with bond angles of $109.5^\circ$.

Graphite

An allotrope of carbon forming hexagonal layers of carbon atoms bonded to three others with bond angles of $120^\circ$, containing delocalised electrons and weak intermolecular forces between layers.