AQA GCSE Chemistry Paper 1 Revision Combined

Element

Substance made from one type of atom

Molecule

Fixed number of atoms covalently bonded

Compound

Two or more different elements chemically combined

Separation of sand and water

Filtration

Separation of a mixture of liquids

Fractional distillation

Separation of dyes

Chromatography

Mixture

Combination of substances in any proportion

Relative atomic mass

Average mass of an atom of an elemnt compared with one atom of C-12

Isotope

Atoms of the same element with the same protons but different neutron

Ionic bond between

metal & non-metal

Covalent bond between

non-metals

Ionic bond electrons are

Transferred from metal to non-metal

Covalent bond electrons are

shared

Conductivity of giant ionic structures

Solid = insulator Liquid/solution= conducts

State symbol solid

(s)

State symbol liquid

(l)

State symbol gas

(g)

State symbol solution

(aq)

Simple molecules low melting point

Weak intermolecular forces

Giant covalent structures melting point

Breaking many strong covalent bonds

Moles of solid

m/Mr

Linking many monomers

Polymer

Many ethene linked

Polyethene

Particles in solid

Regular arrangement, vibrating around fixed positions

Particles in liquid

Move and slide over one another

Pariticlesd in a gas

Rapid, random motion

Group 7

Halogens

Group 7 reactivity

Increases up the group

Number of atoms in 12g of C-12

Avogadro's number

Atom Economy

relative mass of useful / relative mass of reactants x100

Oxidation (electrons )

Loss of electrons

Reduction ( electrons)

Gain of electrons

Metal + Oxygen

Metal oxide

Metal + Water

Metal hydroxide + hydrogen

Metal + Steam

Metal oxide + hydrogen

Metal + Acid

Metal Salt + hydrogen

Releasing heat energy

Exothermic

Takin in heat energy

Endothermic

Curve of liquid in narrow tube

Meniscus

Phenolphthalein in acid

Colourless

Phenolphthalein in alkali

Pink

Exact reaction of acid & alkali

Titration

Moles of gas

v/24000

Copper + Hydrochloric acid

No reaction

Magnesium + Copper sulphate

Magnesium sulphate + copper

Oxidation and reduction

Redox reaction

Titration precision

Dropwise, white tile, repeat

Results within 0.1cm3

Concordant

Displacement of metals

Temperature increases

Structure that insulates as solid but conducts when melted or dissolved

Giant Ionic

Structure with a low boiling point as weak intermolecular forces

Covalent Molecular

Structure with a very high melting point due to many strong covalent bonds

Giant Covalant

Structure that conducts electricity and can react with water

Metallic

Bond made by sharing electrons

Covalent

Bond made by transferring electrons

Ionic

Bonding between positive ions ( cations ) and delocalised electrons

Metallic

Bonding between metals and non-metals

Ionic

Bonding between non-metals

Covalent

Force between simple molecules

Intermolecular

Force between oppositely charged ions

Electrostatic

Electrons which are free to move

Delocalised

Metals conduct because of

Delocalised electrons

Graphite conducts because of

Delocalised electrons

Giant ionic solids do not conduct because

Ions are not free to move

Giant ionic liquids / solutions conduct because

Ions are free to move

Giant covalent molecule that conducts electricity is

Graphite

Number of covalent bonds per carbon in diamond

4 bonds

Number of covalent bonds per carbon in graphite

3 bonds

Structure of NaCl

Giant Ionic

Structure of MgO

Giant Ionic

Structure of H2O

Simple molecular

Structure of sand, mainly SiO2

Giant covalent

Structure of iron

Metallic

1nm-100nm

Nanoparticle range

Advantage of nanoparticles

Large volume : surface area ratio

Single sheet of graphite is called

graphene

C60

Buckminsterfullerene

Democritus

Named the atom after the Greek word "atomos" which means indivisible; believed there is a limit to how many times one can break matter into smaller pieces; eventually one reaches the smallest particle.

Dalton's model of the atom

Billiard Ball model; Indivisible, indestructible, solid sphere

Thomson's model of the atom

Plum-pudding model; Positive charge spread over the sphere with negatively charged electrons inside

Gold Foil Experiment

Alpha particles that were shot at gold foil were deflected when they hit the positive center of gold atoms; the nucleus was discovered as a result of this experiment.

Rutherford's model of the atom

Nuclear model; A tiny nucleus (positive charge) around which electrons (negative) orbit

Bohr's model of the atom

Planetary model; The electrons orbit nucleus at discreet orbits which correspond to energy levels

Atom

Smallest particle of an element

Nucleus

Centre of the atom, holds the protons and the neutrons

Protons

Charge +1 Mass 1

Neutrons

Charge 0 Mass 1

Electrons

Charge -1 Mass 1/1840

Atomic Number

Equal to the number of protons

Mass Number

Equal to the number of protons + number of neutrons

Periodic Table

A chart of the elements showing the repeating pattern of their properties

Isotope

Atoms of the same element that have same number of protons but a different numbers of neutrons

Electron Configuration

the arrangement of electrons in the orbitals of an atom

Electrons in first shell

up to 2

Electrons in second shell

up to 8

Electrons in third shell

up to 8

Enthalpy change

Heat energy change

Exothermic

Releases heat energy ( gets hotter )

Endothermic

Takes in heat energy ( gets cooler )

Energy profile diagram - exothermic

Products higher in energy than reactants