Chemistry for Cambridge IGCSE: Coursebook Review

Comprehensive practice flashcards for students reviewing the Cambridge IGCSE Chemistry syllabus, covering states of matter, atomic theory, bonding, stoichiometry, and environmental chemistry based on the coursebook lecture notes.

How is matter defined in chemistry?

Anything that occupies space and has mass.

What are the three physical states of matter?

Solid, liquid, and gas.

What is the difference between solids and fluids (liquids/gases) regarding shape?

Solids have a definite, fixed shape, while fluids have no definite shape and take the shape of their container.

What occurs during the process of sublimation?

A substance changes directly from a solid to a gas, or gas to a solid, without passing through the liquid phase.

How is the boiling point of a pure liquid defined?

The specific temperature at which the pressure of the gas created above the liquid equals atmospheric pressure.

What identifies a pure substance in terms of melting and boiling points?

A pure substance consists of only one element or compound and has precise, predictable melting and boiling temperatures.

What is the effect of impurities on the freezing point of water?

Impurities cause water to freeze at a temperature below the standard freezing point of $0\,^\circ C$.

Define a lattice in the context of solids.

A regular, three-dimensional arrangement of particles ($atoms$, $molecules$, or $ions$) in a crystalline structure.

What are the three main points of the kinetic particle theory?

1. All matter consists of small particles. 2. Particles are consistently in motion. 3. Particle motion and arrangement vary by state (solid, liquid, or gas).

What is the relationship between temperature and the kinetic energy of particles?

As temperature increases, the average energy and speed of the particles also increase.

Define intermolecular space.

The distance between particles in a substance, which is very small in liquids but uniquely large in gases.

What characterizes an exothermic change?

A process where heat energy is released to the surroundings, resulting in a negative enthalpy change ($\Delta H$).

What is a mixture according to the text?

Two or more substances that are physically combined but not chemically bonded together.

What characterizes a saturated solution?

A solution that contains the maximum possible amount of dissolved solute at a specific temperature.

Define diffusion in fluids.

The process where particles mix by moving randomly from a region of higher concentration to a region of lower concentration until evenly spread.

What are the relative mass and relative charge of a proton?

Protons have a relative mass of $1$ and a relative charge of $+1$.

Where are protons, neutrons, and electrons located within an atom?

Protons and neutrons are in the central nucleus, while electrons orbit in shells outside the nucleus.

Explain the difference between proton number ($Z$) and mass number ($A$).

The proton number is the number of protons in the nucleus, while the mass number is the sum of both protons and neutrons.

What are isotopes?

Atoms of the same element with the same number of protons but a different number of neutrons.

What determines why isotopes of an element share the same chemical properties?

They have the same number of electrons and identical electronic configurations.

How many electrons can the first and second energy levels (shells) hold?

The first level holds a maximum of $2$ electrons, and the second holds up to $8$.

Define an ionic bond.

A strong electrostatic force of attraction between oppositely charged ions.

What occurs when a metal atom forms a cation?

It loses its outer shell electrons to achieve a stable noble gas configuration, resulting in a positive charge.

Define a covalent bond.

A chemical bond formed by the sharing of one or more pairs of electrons between two atoms.

What is metallic bonding?

The electrostatic attraction between a regular array of positive metal ions and a 'sea' of mobile, delocalised electrons.

What makes metals malleable and ductile?

Metal atoms are arranged in layers that can slide over each other without breaking the structure when force is applied.

Contrast molecular and empirical formulae.

Molecular formulae show the actual number of atoms in a molecule, while empirical formulae show the simplest whole-number ratio of atoms.

What is the Avogadro constant ($L$)?

The number of atoms, molecules, or ions in $1\,mol$ of any substance, which is $6.02 \times 10^{23}$.

What is the molar gas volume at room temperature and pressure (r.t.p.)?

One mole of any gas occupies a volume of $24\,dm^3$ (or $24\,litres$).

Define activation energy ($E_a$).

The minimum amount of energy required for a chemical reaction to occur.

According to collision theory, how does concentration affect reaction rate?

Increasing concentration puts more reactant particles in a unit volume, increasing the frequency of successful collisions.

What is a dynamic equilibrium?

A state in a closed system where the forward and reverse reactions occur at exactly the same rate, keeping concentrations constant.

State the standard industrial conditions for the Haber process.

A temperature of $450\,^\circ C$, a pressure of $20000\,kPa$ ($200\,atmospheres$), and a finely divided iron catalyst.

What are the percentages of the primary gases in clean dry air?

$78\%$ nitrogen, $21\%$ oxygen, and $0.9\%$ argon.

Why is carbon monoxide ($CO$) considered toxic?

It binds irreversibly to haemoglobin in red blood cells, preventing the transport of oxygen.

Define a polymer.

A large molecule made up of many small repeating units known as monomers joined together.

What defines an acid in terms of proton transfer?

An acid is a substance that acts as a proton donor.

What characterizes a strong acid compared to a weak acid?

A strong acid dissociates completely into ions in water, while a weak acid only dissociates partially.