Chemistry

Melting

solid to liquid

Freezing

liquid to solid

Evaporation

liquid to gas below boiling point

Boiling

liquid to gas

Condensation

gas to liquid

Sublimation

solid to gas

Deposition

gas to solid

Diffusion

net movement of particles from an area of high concentration to an area of low concentration (only in liquids/gases)

Brownian Motion

random motion of particles in a fluid due to collisions with molecules

Concentration

a measure of the amount of substance (solute) dissolved in a specific volume of solvent, where the units are typically mol/dm3

Dilution

the addition of water to a solution to reduce the amount of solute particles present in a given volume

Metallic Bond

electrostatic force of attraction between a sea of negative delocalised electrons and positive metal ions in a metal lattice

Alloy

mixture of a metal with small amounts of other elements

Anhydrous

dehydrated

Base

metal oxide/hydroxide/carbonate

Alkali

soluble base

strength

how much an acid dissociates in water

Concentration

amount of acid per unit of volume

Fully dissociates

all particles split into ions in water

Partially dissociates

some particles split into ions in water

Concentrated

more acid per unit of volume

dilute

less acid per unit of volume

Burette

glass tube that delivers precise liquid volumes (e.g. in titrations)

Titre

volume of acid or alkali added during a titration

Neutralisation

a reaction where acids react with alkalis or bases to form a salt and water

Element

substance made of only one type of atom that can’t be split into anything simpler by chemical means

Compound

formed when two or more elements chemically combine, harder to separate with a fixed melting/boiling point

Mixture

various substances mixed but not chemically bonded together that can be separated by physical means and melts/boils over a range of temperatures

Groups

vertical columns; tells you number of electrons in outer shell

Periods

horizontal rows; tells you number of electron shells

Atom

smallest piece of an element that can still be recognised as that element

Atomic/Proton number

number of protons in an atom’s nucleus which determines the element; same as number of electrons (unless ion)

Mass/Nucleon number

total number of protons and neutrons in the nucleus of the atom

Isotope

atom with the same proton number but different number of neutrons (i.e. different mass number)

electronic configuration

arrangement of electrons in an atom

anions

negative ions formed by the gain of electrons (non metals)

cations

positive ions formed by the loss of electrons (metals)

Ag

+

Cu

2+

Pb

2+

Zn

2+

NH₄

+

CO₃

2-

NO₃

-

SO₄

2-

Ionic bond

electrostatic force of attraction between positive metal ions and negative non metal ions

redox

when oxidation and reduction take place simultaneously

Oxidation is…

loss of electrons, gain of oxygen

Reduction is…

gain of electrons, loss of oxygen

oxidising agent

substance that is reduced

reducing agent

substance that is oxidised

Relative Atomic Mass (A_r)

the mean weighted mass of all isotopes of an element relative to C-12, which has a mass of 12

Isotope

atoms of the same element which have the same number of protons but a different number of neutrons

Metal oxides are…

basic

Non metal oxides are…

acidic

Alloy

mixture of a metal with small amounts of other elements

Anhydrous

dehydrated

Rust

iron oxide (Fe2O3)

All metals…

corrode

Rusting is a form of…

corrosion

Electrolysis

breaking down of ionic substances using electricity

Electrolyte

molten or aqueous compound being electrolysed - must contain free moving ions

slag

waste material formed during electrolysis

metal ore

a rock that contains enough of the metal to make it worthwhile extracting

native state

how unreactive metals are found - as an uncombined element

distillation

evaporation then condensation to separate a soluble salt from a solvent

pure

one type of substance - melts/boils at specific temperature

solute

substance that dissolves in a solvent (e.g. table salt)

solvent

substance that dissolves a solute (e.g. water)

solution

mixture of solute and solvent (e.g. saltwater)

saturated solution

a mixture that has dissolved the maximum amount of solute possible

chromatography

technique used to separate a mixture of soluble substances

precipitate

gelatinous solid in a solution

coke

fuel in a blast furnace that reduces iron ore to iron and provides heat

covalent bond

EFoA between a shared pair of negative elctrons and the positive nuclei of two non-metals

allotrope

consist of the same atoms but bonded differently

actual yield

the amount of product you really get in the experiment after practical losses

theoretical yield

maximum amount of product you could get if the reaction were perfect