CAIE IGCSE Chemistry (0620) Lecture Notes Flashcards

Vocabulary practice flashcards based on CAIE IGCSE Chemistry theory, covering states of matter, atomic structure, stoichiometry, reactions, and laboratory, and environmental chemistry contents.

States of Matter

The different forms in which matter can exist, which are Solid, Liquid, and Gas.

Solids

A state of matter where particles are arranged regularly in a lattice, have a fixed volume, and a definite shape.

Liquids

A state of matter where particles are randomly arranged and can move past one another, taking the shape of their container with a fixed volume.

Gases

A state of matter with particles that are mobile and move randomly, having no fixed volume and taking the shape of their container.

Boiling

An endothermic process where a liquid converts to a gas at a set temperature throughout the liquid.

Evaporation

A slow endothermic process where a liquid converts to a gas at any temperature above the freezing point, only occurring at the surface.

Condensation

The process by which a gas converts into a liquid, occurring at the same temperature as the boiling point.

Sublimation

The change of state from solid directly to gas.

Diffusion

The net movement of particles from a region of higher concentration to a region of lower concentration as a result of Brownian motion.

Elements

Substances made of atoms that share the same number of protons and cannot be broken down by chemical methods.

Compounds

Two or more elements chemically bonded together in a fixed proportion.

Mixtures

Two or more substances not chemically bonded together.

Atoms

The building blocks of all matter, consisting of a central nucleus (containing protons and neutrons) surrounded by electron shells.

Proton

A subatomic particle with a relative mass of $1$ and a relative charge of $+1$.

Electron

A subatomic particle with a relative mass of $\frac{1}{1840}$ and a relative charge of $-1$.

Neutron

A subatomic particle with a relative mass of $1$ and a relative charge of $0$, serving to hold the nucleus together.

Proton Number (Atomic Number)

Denoted by the letter $Z$, it is the unique number of protons in the nucleus of an atom.

Nucleon Number (Mass Number)

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Different atoms of the same element with the same number of protons but different numbers of neutrons.

Metallic Bonding

The electrostatic attraction between the positive ions in a giant metallic lattice and a sea of delocalised electrons.

Covalent Bond

Pairs of electrons shared between two atoms leading to a noble gas electronic configuration ($2.8.8$).

Ionic Bonds

Strong electrostatic attraction between oppositely charged ions, typically formed between metals and non-metals.

Molecular Formula

The number and type of different atoms in one molecule.

Empirical Formula

The simplest whole number ratio of the different atoms or ions in a compound.

Relative Atomic Mass ($A_r$)

The average mass of the isotopes of an element compared to $\frac{1}{12^{th}}$ of the mass of an atom of ${^{12}C}$.

Mole

The amount of substance that contains the same number of units as carbon atoms in $12\,g$ of ${^{12}C}$, equal to $6.02 \times 10^{23}$ particles.

Electrolysis

The decomposition of an ionic compound, when molten or in aqueous solution, by the passing of an electric current.

Anode

The positive electrode where oxidation of negative anions occurs.

Cathode

The negative electrode where reduction of positive cations occurs.

Electroplating

The process of coating the surface of a metal with another metal using electrolysis to prevent corrosion or enhance appearance.

Exothermic Reaction

A reaction where heat energy is released into the surroundings, and the surrounding temperature increases.

Endothermic Reaction

A reaction where heat energy is absorbed from the surroundings, resulting in a temperature decrease.

Activation Energy ($E_a$)

The minimum energy required for a chemical reaction to take place.

Catalyst

A substance that increases the reaction rate by lowering the activation energy while remaining unchanged at the end of the reaction.

Le Ch\u00e2telier\u2019s Principle

If conditions of equilibrium are changed, the position of the equilibrium moves to oppose that change.

Redox

A simultaneous oxidation and reduction reaction.

Acid

A proton donor that produces hydrogen ions ($H^+$) when dissolved in water.

Base

A proton acceptor that neutralises acids to form salt and water.

Amphoteric Oxides

Oxides that can react with both acids and bases to form salt and water, such as $ZnO$ and $Al_2O_3$.

Alloy

A mixture of two or more metals, or a metal and a non-metal, which is typically harder and stronger than pure metals.

Rusting

The corrosion of iron and steel to form hydrated iron (III) oxide ($2Fe_2O_3\cdot H_2O$) in the presence of water and oxygen.

Homologous Series

A group of organic compounds with similar chemical properties, the same functional group, and the same general formula.

Structural Isomers

Compounds with the same molecular formula but different structural formulas.

Hydrocarbons

Organic compounds containing only carbon and hydrogen atoms.

Alkanes

Saturated hydrocarbons with single carbon-carbon bonds and the general formula $C_nH_{2n+2}$.

Alkenes

Unsaturated hydrocarbons containing at least one carbon-carbon double bond ($C=C$).

Polymers

Large molecules built up from small units known as monomers.

Rf Value

Used in chromatography to identify a substance, calculated as the distance moved by the substance divided by the distance moved by the solvent.