EOY Exam flashcards
atom
the smallest unit of matter
element
a substance made of only 1 type of atom
molecule
a substance made of two or more atoms joined together by a bond
compound
a substance made of at least two different types of atom chemically bonded together
mixture
two or more substances that are mixed together but are not joined by bonds
chemical symbol
the letters on the periodic table that give the name of each element, every element has its own chemical symbol
chemical formula
the collection of chemical symbols that show how many of each element are present in a molecule or compound
nucleus
the centre part of an atom that contains the protons and neutrons
proton
sub-atomic particle that makes up the nucleus of an atom, has a mass of 1 and a charge of +1
neutron
sub-atomic particle that makes up the nucleus of an atom, has a mass of 1 and a charge of 0
electron
sub-atomic particle found orbiting the nucleus in an electron shell, has a mass of almost 0 and a charge of -1
ion
an atom that has lost or gained electrons to become charged, lost electrons leave a positive ion, gained electrons leave a negative ion
conservation of mass
a rule that says you must have the same amount of atoms at the end of a chemical reaction as you started with
chemical equation
a way of showing what happens in a chemical reaction using the chemical symbols and formulae of the substances
balanced equation
a chemical equation written so that there are the same number of each type of atom on each side of the equation
atomic number
the smaller number next to the chemical symbol that identifies an element and gives the number of protons and electrons in that atom
mass number
the larger number next to the chemical symbol of an element that measures the mass of the atom (Mass number = number of protons + number of neutrons)
electronic structure
a diagram showing how the electrons are arranged in the electron shells (the 1st shell can have a maximum of 2 electrons, the others can hold up to 8 electrons)
electron shell
one of the regions outside of the nucleus where electrons can be found
filtration
a technique used to separate an insoluble substance from a solvent (one that does not dissolve)
crystallisation
a technique used to separate a soluble solid (or salt) from a solution
distillation
a technique used to obtain the solvent (or liquid) from a solution
fractional distillation
a technique used to separate two miscible liquids (ones that do mix together)
chromatography
a technique commonly used to separate a mixture of dyes in ink
J.J. Thomson
the scientist who discovered the electron and proposed the plum pudding model
plum pudding model
a model of the atom that proposed the nucleus was a ball of positive charge with negative electrons embedded in it (we now know this is incorrect)
Rutherford’s experiment
the experiment that proved the nucleus must be positively charged (as alpha particles were scattered/deflected by a piece of gold foil)
Niels Bohr
the scientist who proposed that electrons are found in shells
James Chadwick
the man who proposed the existence of neutrons
isotope
atoms of the same elements with the same atomic number but different mass numbers (different numbers of neutrons in the nucleus)
periodic table
the way in which the elements are organized and classified
John Dalton
the scientist who proposed one of the first periodic tables, he organized the elements in order of atomic weight
John Newlands
the scientist who built on the ideas of Dalton and arranged elements into sets of eight (as he found that each eighth element had similar properties)
Dmitri Mendeleev
the Russian chemist who proposed the periodic table we use today- he left gaps for undiscovered elements
atomic number
elements on the periodic table are placed in order of this number
group
a column going down in the periodic table
period
a row going across in the periodic table
metals
the elements found to the left of the periodic table, they are electrical conductors
non-metals
the elements found in the top right-hand corner of the periodic table, they are electrical insulators
noble gases
group 0 of the periodic table
alkali metals
group 1 of the periodic table
the halogens
group 7 of the periodic table
transition metals
the middle block of metals in the periodic table, containing elements such as: copper, gold and iron
full electron shell
the reasons the noble gases are so unreactive
group numbe
the number of electrons in the outermost shell of an atom
metal hydroxide + hydrogen
the two products formed when an alkali metal reacts with water
reaction of lithium with water
floats, fizzes steadily until it disappears
reaction of sodium with water
melts to form a ball, fizzes rapidly and may form an orange flame
reaction of potassium with water
fizzes rapidly, sets on fire with a purple flame and a ‘pop’ is sometimes heard at the end of the reaction
the reactivity of the alkali metals…
increases as you go down the group
alkali metals increase in reactivity as you go down the group because…
as the elements get larger the outer electron becomes further away an easier to remove
displacement reaction
a reaction in which a more reactive halogen takes the place of a less reactive halogen
the reactivity of the halogens…
decreases as you go down the group
halogens decrease in reactivity as you go down the group because…
the nucleus is shielded more effectively as you go down the group, so it’s ability to attract an electron gets weaker
three states of matter
solid, liquid and gas
solid
arrangement of particles with a fixed shape and volume, they cannot be compressed at an atomic structure
liquid
arrangement of particles with a fixed volume but they can flow and change shape
gas
arrangement of particles with no fixed shape or volume, they can be compressed easily
particle theory
the theory that is based on the fact that substances are made of tiny particles and describes their movement and the distances between particles
melting point
the temperature at which a solid turns to a liquid
boiling point
the temperature at which a liquid turns to a gas
compound
a substance made of two or more elements chemically bonded together
covalent bonding
bonding between non-metals only, in which electrons are shared
ionic bonding
bonding between metals and non-metals, in which electrons are transferred
positive ion
an atom that loses one or more electrons and gains a positive charge
negative ion
an atom that gains one or more electrons and gains a negative charge
electrostatic attraction
the strong force that holds ions together
giant lattice
the arrangement of ions in ionic bonding results in this structure
NaCl
sodium chloride
MgCl₂
magnesium chloride
Ca(OH)₂
calcium hydroxide
simple molecules
small molecules in which atoms are held together by covalent bonds
giant covalent structures
giant structures where atoms are held together by an array of covalent bonds
polymers
very long molecules made of the same small molecule joined together to make a large molecule
intermolecular forces
weak forces between covalently bonded molecules that must be broken when simple substances melt or boil
diamond
an allotrope of carbon in which all of the carbon atoms are bonded to 4 others resulting in an extremely strong structure
silicon dioxide
a giant covalent structure very similar to diamond but made from silicon and oxygen instead of carbon
graphite
an allotrope of carbon that has hexagonal sheets of carbon with weak attractive forces between the layers
fullerenes
an allotrope of carbon in which the carbon form cage like structures
delocalised electrons
electrons not linked with a particular ion that are free to move through a structure
graphene
a single sheet of carbon atoms (like one layer of graphite)
crystals
metal atoms build up layer upon layer to form these structures
alloys
a mixture of metals, typically much harder than metal atoms alone
ore
a rock from which it is economical to extract the metal it contains
oxidation
addition of oxygen to a substance
reduction
removal of oxygen from a substance
reactivity series
the list of metals by how reactive they are
hydrogen
the gas given off when a metal reacts with acid
metal + acid →
salt + hydrogen
displacement reaction
a reaction in which a more reactive metal displaces a less reactive metal from it’s salt
carbon
the element that can be used to extract a metal from its ore as long as it is less reactive that it (such as copper)
OILRIG
oxidation is loss, reduction is gain (of electrons)
metal oxide + carbon →
metal + carbon dioxide
electrolysis
the method of an extracting a metal more reactive than carbon by using electricity
salt
a compound formed when the hydrogen in an acid is replaced by a metal ions
chloride
the salt formed using hydrochloric acid
sulfate
the salt formed using sulfuric acid
nitrate
the salt formed using nitric acid
acid + base →
salt + water
neutralization
the reaction between an acid and base
acid + alkali →
salt + water
acid + carbonate →
salt + water + carbon dioxide
alkali
a soluble hydroxide (one that dissolves in water)
base
substances that can neutralize acids
acid
substances that can neutralize bases
neutral
a substance that is neither acid or alkaline
pH scale
the scale used to measure how acidic or alkaline a solution is
indicator
a substance that changes colour in acid and alkali
H⁺
the ion found in acids
OH⁻
the ion found in alkalis
soluble salt
a salt that does dissolve in water
insoluble salt
a salt that does not dissolve in water
sulfuric acid + copper oxide →
water + copper sulfate
hydrochloric acid + magnesium →
hydrogen + magnesium chloride
hydrochloric acid + iron oxide →
water + iron chloride
red
the colour of universal indicator in acid
blue/purple
the colour of universal indicator in alkali
green
the colour of universal indicator in neutral solutions
aqueous solution
a solution formed when a substance dissolves in water
electrolysis
the process by which an ionic substance is broken down using electricity
electrolyte
the substance being broken down by electrolysis (solution or molten)
electrode
the conducting rods used in electrolysis
anode
the positively charged electrode
cathode
the negatively charged electrode
anion
a negatively charged ion
cation
a positively charged ion
molten or in solution
the state an ionic compound must be in for it to undergo electrolysis
OILRIG
oxidation is loss, reduction is gain
oxidation
loss of electron
reduction
gain of electrons
positive ions are attracted to
the negative electrode (the cathode)
negative ions are attracted to
the positive electrode (the anode)
cryolite
the substance added to aluminium oxide to lower its melting point
exothermic reaction
a reaction in which energy is released to the surroundings
endothermic reaction
a reaction in which energy is taken in from the surroundings
combustion, neutralization and oxidation
examples of exothermic reactions
thermal decomposition and electrolysis
examples of endothermic reactions
reaction profile
a diagram showing the energies of the reactants and products of a reaction
exothermic reaction profile
reactants- energy is released- products at lower energy level
endothermic reaction profile
reactants- energy is taken in- products at higher energy level
activation energy
the minimum amount of energy required for a reaction to take place
rate of reaction
how fast the reactants turn into the products
mean rate of reaction =
amount of product formed ÷ time
collision theory
particles must have enough energy to collide and collide in the correct orientation for a reaction to happen
activation energy
the smallest amount of energy particles must have before they react
catalyst
a substance that speeds up a chemical reaction without itself being chemically changed
exothermic reaction
a reaction that transfers energy from the reactants to the surroundings (gives off heat)
endothermic reaction
a reaction that transfers energy from the surroundings to the reactants (there is a drop in temperature)
reversible reaction
a reaction in which the reactants make the products and the products make the reactants
temperature
increasing the temperature increases the reaction rate
surface area
increasing the surface area leads to more successful collisions and increases the rate
concentration
increasing concentration means that particles are closer together and there are more collisions increasing the rate of reaction
pressure
increasing pressure means that particles are closer together and there are more collisions increasing the rate of reaction
temperature, concentration, pressure, surface area
the four factors which affect the rate of a reaction
catalysts work by…
lowering the activation energy of a reaction
equilibrium
a reversible reaction in which the rate of the forward and backward reactions is the same
if a reversible reaction is endothermic in one direction…
it is exothermic in the opposite direction
hydrated copper sulfate
blue (contains water)
anhydrous copper sulfate
grey/white powder (without water)
Hydrocarbon
Any compound that contains only hydrogen and carbon atoms
Alkanes
Simple type of hydrocarbon. Have C-C single bond. Saturated compounds from the homologous series
Alkanes Formula
C(n)H(2n+2)
Complete Combustion Equation
Hydrocarbon + Oxygen > Carbon dioxide + Water
Hydrocarbon Properties
Shorter length - more runny, more volatile, more flammable, lower boiling points
Uses Of Hydrocarbons
~C3 = liquid petroleum gas
~C8 = petrol
~C15 = kerosene
~C20 = diesel oil
~C40 = heavy fuel oil
Fractional Distillation
The process of separating different sized hydrocarbons from crude oil
Crude Oil
A fossil fuel formed from the remains of plants and animals, mainly plankton, that died millions of years ago and were buried in the mud at the bottom of the ocean
Fractional Distillation Process
1) Oil heated until it mostly turns to gas - enters fractional distillation column
2) Longer hydrocarbons liquidise early and drain out near the bottom
3) Shorter hydrocarbons liquidise later and drain our nearer the top
4) You end up with differently purposed hydrocarbons separated out
Bitumen
Extremely long-chained hydrocarbon used in road tarmac
Uses Of Crude Oil
Fuel for most modes of transport, petrochemical industry
Cracking
The splitting up of long-chain hydrocarbons into shorter chains
Process Of Cracking
1) Heat long-chained hydrocarbons to vapourise them
2) Pass vapour over a hot aluminium oxide catalyst (~550 ºC)
3) Molecules are split apart on the surface - catalytic cracking
or
4) Mix with steam and heat to a very high temperature - steam cracking (~800 ºC and no catalyst)
Alkenes
Unsaturated hydrocarbons with a carbon double bond
Formula For Alkenes
C(n)H(2n
Alkenes Equation
Alkene + Oxygen => Carbon or Carbon Dioxide or Carbon Monoxide + Water (depending on how much oxygen is available, different amounts of carbon compounds will be made)
Hydrogenation
Reaction of an alkene and hydrogen
Alkene + Steam (water)
Forms an alcohol
Bromine + Ethene
Forms dibromoethene
Alcohols
1) -OH functional group
2) Names end in -ol
Uses Of Alcohols
Solvents and fuels
Fermentation Equation
Sugar => Ethanol + Carbon Dioxide
Carboxylic Acids
1) -COOH functional group
2) React with carbonates to form a salt, water and carbon dioxide
Esters Equation
Alcohol + Carboxylic Acid > Ester + Water
Esters
1) -COO- functional group
2) Acid Catalyst needed in a reaction to form them
Types Of Polymerisation
Addition and condensation
Addition Polymerisation
1) One monomer type
2) Only forms one product
3) Carbon-Carbon double bond in monomer (C=C)
Condensation Polymerisation
1) Two monomer types with two of the same functional group OR one monomer type with two different functional groups
2) Two products - polymer + small molecule
3) Two functional groups on each monomer
Amino Acid Groups
Amino group and carboxyl group
DNA Molecules
1) Found in every living thing
2) Contains genetic instructions
3) Double Helix structure
4) Made of Polymer chains ‘nucleotides’
Simple Sugars
Small molecules containing carbon, oxygen and hydrogen. Can react together to form larger carbohydrate polymers such as starch
