Chemistry Topic 2 – Bonding, Structure and the Properties of Matter

Vocabulary flashcards covering key definitions, states of matter, heating curves, and properties of simple covalent molecules from Chemistry Topic 2.

Covalent bond

The bond between two non-metal atoms that share one or more pairs of electrons.

Ionic bond

The electrostatic force of attraction between positively and negatively charged ions.

Dot and cross diagram

A diagram showing only the arrangement of the outer shell electrons of the atoms or ions in a substance.

Giant lattice structure

A huge 3D network of atoms or ions.

Ion

A charged particle formed by the loss or gain of electrons.

Intermolecular forces

The attraction between the individual molecules in a covalently bonded substance.

Polymers

A substance made from very large molecules made up of many repeating units.

Giant covalent structures

A huge 3-D network of covalently bonded atoms.

Delocalised electrons

Bonding electrons that are no longer associated with any one particular atom.

Fullerenes

A form of the element carbon that can exist as large cage-like structures, based on hexagonal rings of carbon atoms.

Alloy

A mixture of two or more elements, at least one of which is a metal.

Solid (particle model)

Particles touch their neighbours in a regular pattern and vibrate about fixed positions.

Liquid (particle model)

Particles are closely packed randomly together in an irregular arrangement and can move or slide over each other.

Gas (particle model)

Particles are widely spaced apart and move randomly in all directions at various speeds.

Melting and boiling points relationship to particle forces

The stronger the forces between the particles of a substance, the higher the melting and boiling point, as more energy is needed to change state.

Melting (heating curve)

The stage where energy transferred from the surroundings breaks forces between particles until they can move around, with temperature staying constant until all solid becomes liquid.

Boiling (heating curve)

The stage where transferred energy breaks particles apart further until all liquid becomes gas, overcoming the forces between particles at a constant temperature.

Simple covalent molecules

Small molecules formed when atoms share pairs of electrons through very strong covalent bonds, having weak intermolecular forces between molecules.

Melting and boiling behavior of simple covalent molecules

They have low melting and boiling points because only the weak intermolecular forces between molecules are broken when melted or boiled, not the strong covalent bonds.

Electrical conductivity of simple covalent molecules

They do not conduct electricity because the molecules do not carry an overall electrical charge.

Molecular size effect on intermolecular forces

As the size of the molecule increases, the intermolecular forces between the molecules increase, causing the melting and boiling points to increase.