Book 1: Definitions Flashcards
Element
A pure substance that cannot be broken down into anything simpler by chemical methods.
Compound
A pure substance that consists of two or more elements chemically joined together.
Mixture
It is made up of two or more substances (elements or compounds) that are not chemically joined together.
Solute, solvent, solution
Solute + solvent = solution
Dilute solution
It contains a small amount of solute in a given volume of solution.
Concentrated solution
It contains a large amount of solute in a given volume of solution.
Saturated solution
It contains solute such that no more solute dissolved in the solution at the temperature.
Filtrate
Substances that pass through the filter paper in filtration.
Residue
Substances that are trapped on the filter paper in filtration.
Distillate
Liquid product condensed from vapour in distillation.
Physical change
A change in which no new substance is formed.
Chemical change
A change in which at least one new substance is formed.
Physical properties
Properties that can be observed or measured without changing the chemical composition of the substance.
Chemical properties
Properties that can be observed or measured without changing the chemical composition of the substance only when the substance undergoes a chemical change to form new substances.
Ores
Rocks containing minerals in concentrations that are high enough for economical extraction.
Effervescence
Bubbling / fizzing
Weathering
The process where rock is dissolved, worn away or broken down into smaller and smaller pieces.
Erosion
The process of moving weathered rock materials to another place by ice, water, wind, or gravity.
Atom
The smallest particle of an element that still has its chemical properties.
Brittle
Appears hard on the surface but breaks easily.
Malleable
Can be hammered into a shape
Ductile
Can be drawn into a wire
Metalloids
Elements that do not fit easily into metals or non-metals.
Semi-conductor
Pure form does not conduct electricity, conductivity increases when impurity is added.
Z
Atomic number
Atomic number (Z)
Number of protons in an element.
A
Mass number
Mass number (A)
Sum of numbers of protons and neutrons of an atom.
Isotopes
Difference atoms of an element which have the same number of protons but a different number of neutrons.
Relative isotopic mass
Mass of an isotope of an element, relative to 1/12 the mass of a carbon-12 atom.
Relative atomic mass
Weighted mean mass of an element taking in to account the relative abundance of isotopes in a naturally occurring sample of the element, relative to 1/12 the mass of a carbon-12 atom.
Transition metals
Metals between group II and group III of the periodic table.
Period number
Indicates the number of occupied electron shells on an atom of the element.
Group number
Indicates the number of outermost shell electrons in an atom of the element.
Alkali metals
Elements in group I
Alkaline earth metals
Elements in group II
Halogens
Elements in group VII
Noble gases
Elements in group 0
Chemically inert
Rarely react with other substances
Monoatomic ion
Formed when one atom loses or gains one or more electrons.
Cation
Positive ion
Anion
Negative ion
Cation formation
An atom of a metal (/ hydrogen) loses one or more outermost shell electrons.
Anion formation
An atom of a non-metal gains one or more outermost shell electrons.
Charge of monoatomic cation
Group number of the element
Charge of monoatomic anion
8 - group number of the element
Conductors
Substances which conduct electricity but are not chemically changed during electrical conduction.
Electrolytes
Substances which conduct electricity in molten state or aqueous solution but not in solid state, and are decomposed during the conduction.
Non-conductors
Substances that do not conduct electricity in solid, molten state, or aqueous solution.
Ionic bond
The strong electrostatic forces of attraction between oppositely charged ions.
Ionic bond formation
Electrons are transferred from one atom (a group of atoms) to another (or group of atoms).
Oxoanion
Polyatomic anion with oxygen
Polyatomic ions
Ione formed from a group of atoms
Chemical formula
A way to represent a chemical substance by using symbols and numbers.
Delocalised electrons
Outermost shell electrons of atoms of metals that become free and move randomly throughout the metal.
Metallic bond
The strong electrostatic forces of attraction between positive metal ions and a “sea” of delocalised electrons.
Covalent bond formation
Two atoms share a pair of electrons.
Covalent bond
The strong electrostatic forces of attraction between the positively charged nuclei of the two bonded atoms and the negatively charged shared electrons.
Molecular formula
Formula of a substance that gives the total number of atoms of each element present in one molecule of the substance.
Lone pair of electrons
A pair of electrons in the outermost shell of one of the atoms in a molecule which is not involved in bonding.
Double bond formation
When two pairs of electrons are shared between two atoms in a molecule.
Triple bond formation
When three pairs of electrons are shared between two atoms in a molecule.
Dative covalent bond
A type of covalent bond in which both electrons come from the same atom.
Relative molecular mass
(For an element of a compound existing as discrete molecules) The sum of the relative atomic masses of all the atoms which make up one molecule.
Formula mass
(For ionic compounds) The sum of the relative atomic masses of all the atoms in one formula unit of the compound.
Non-aqueous solvent
Any solvent other than water
Allotropes
Two or more forms of the same element in which the atoms or molecules are arranged in different ways.
Minerals
Metals combined with other elements chemically as compounds
Ores
Rocks containing minerals in concentrations that are high enough for economical extraction.
Roasting
The process in which the concentrated ore is heated strongly in the presence of excess air.
Calcination
The process in which the concentrated ore is heated strongly in the absence or limited supply of air.
Displacement reaction
A reaction in which a stronger oxidising agent displaces a weaker oxidising agent from its ions in a solution.
Spectator ions
Ions which do not change in chemical nature nor physical state during a reaction.
Avogadro constant
6.02 x 1023 mol-1
Molar mass
Mass of one mole of a substance (g mol-1)
Water of crystallisation
Water necessary for the formation of crystals of some compounds
Hydrated compounds
Compounds containing water of crystallisation
Anhydrous compounds
Compounds not containing water of crystallisation
Empirical formula
A formula of a compound that gives the simplest whole number ratio of atoms or ions in the compound.
Limiting reactant
The reactant which is used up in a chemical reaction
Reactant in excess
The reactant which is not used up in a chemical reaction
Corrosion
The deterioration of a metal caused by chemical interaction with oxygen, moisture or other substances in the environment.
Rusting
The corrosion of iron
Tin-plating
Coating iron or steel objects with a layer of tin
Electroplating
The process of coating an object with a thin layer of a metal using electrolysis.
Galvanising
Coating iron or steel objects with a layer of zinc
Impressed current cathodic protection
A technique used to prevent the rusting of iron by making ti the cathode of an electric circuit.
