Edexcel IGCSE Chemistry - Topic 1: Principles of Chemistry

Vocabulary flashcards for Edexcel IGCSE Chemistry Topic 1: Principles of Chemistry.

States of Matter

Solid, liquid, and gas, characterized by the arrangement, movement, and energy of their particles.

Gas

State of matter with particles having the most energy and a random arrangement.

Liquid

State of matter with particles having more energy than solids but less than gases, with a random arrangement but closer together.

Solid

State of matter with particles having the least energy, vibrating in place, and arranged regularly and closely together.

Melting

The interconversion process where a solid changes into a liquid.

Freezing

The interconversion process where a liquid changes into a solid.

Boiling

The interconversion process where a liquid changes into a gas.

Condensing

The interconversion process where a gas changes into a liquid.

Diffusion

Movement of particles from an area of high concentration to an area of low concentration.

Solvent

A liquid in which a solute dissolves.

Solute

A substance that dissolves in a liquid to form a solution.

Solution

A mixture formed when a solute has dissolved in a solvent.

Saturated Solution

A solution in which no more solute can be dissolved.

Solubility

The grams of a solute that will dissolve in 100 g of water.

Unsaturated solution

Any mass below the line for a solute at a specific temperature

Supersaturated solution

Any mass above the line for a solute at a specific temperature; unstable

Element

A substance made from only one type of atom.

Compound

A substance made from two or more elements that have reacted chemically with each other.

Mixture

Consists of two or more elements or compounds not chemically combined together.

Pure substance

A single element or compound, not mixed with any other substance.

Simple Distillation

Used to separate a solvent from a solution, especially when the solute has a much higher boiling point.

Fractional Distillation

Used to separate a pure liquid from a mixture of liquids with different boiling points.

Filtration

Separates an insoluble solid (precipitate) from a solution.

Crystallisation

Separates a soluble salt from a solution by evaporation and cooling.

Paper Chromatography

An analytical technique for separating compounds by their relative speeds in a solvent as it spreads through paper.

Pigment

Solid, colored substance

Rf Value

distance moved by substance / distance moved by solvent

Atom

The smallest piece of an element that can exist.

Molecule

Formed when atoms join together by chemical bonds; can be made of atoms of the same element.

Proton

Subatomic particle with a relative mass of 1 and a relative charge of +1, located in the nucleus.

Neutron

Subatomic particle with a relative mass of 1 and a relative charge of 0, located in the nucleus.

Electron

Subatomic particle with a relative mass of 1/1836 and a relative charge of -1, located in shells around the nucleus.

Atomic Number

The number of protons in an atom (also the number of electrons in a neutral atom).

Mass Number

The number of protons plus neutrons in an atom's nucleus.

Isotopes

Different atoms of the same element containing the same number of protons but different numbers of neutrons in their nuclei.

Relative Atomic Mass (Ar)

An average value that takes account of the abundance of the isotopes of the element.

Electronic Configuration

How many electrons are in each shell around an electron’s nucleus

Metals

Elements that react to form positive ions, are generally conductive, and have basic oxides.

Non-metals

Elements that do not form positive ions, are generally not conductive, and have acidic oxides.

Word Equation

A chemical equation using the names of the substances involved.

Balanced Chemical Equation

A chemical equation with the same number of each type of atom on both sides of the equation.

Relative Formula Mass (Mr)

The sum of the relative atomic masses of the atoms in the numbers shown in the formula.

Mole (mol)

The unit for the amount of a substance, numerically equal to its relative formula mass in grams.

Percentage Yield

Amount of product produced / Maximum amount of product possible x 100

Molecular Formula

the number of atoms of each element in a compound

Empirical Formula

the simplest whole number ratio of atoms of each element in a compound

Ions

Atoms that have lost or gained electrons.

Cation

Positive ion

Anion

Negative ion

Ionic Bonding

A giant structure of ions held together by strong electrostatic forces of attraction between oppositely charged ions

Covalent Bond

Formed between atoms by the sharing of a pair of electrons.

Intermolecular Forces

Forces of attraction between molecules; weak in substances with simple molecular structures.

Diamond

Each carbon is joined to 4 other carbons covalently; very hard, has a very high melting point and does not conduct electricity.

Graphite

Each carbon is covalently bonded to 3 other carbons, forming layers of hexagonal rings, which have no covalent bonds between the layers and can conduct electricity.

Fullerenes

Molecules of carbon atoms with hollow shapes

Metallic Bonding

Strong electrostatic attraction between negatively charged electrons and positive metal ions.

Electrolysis

Ions are discharged at the electrodes producing elements

Oxidation

Loss of electrons

Reduction

Gain of electrons