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Chemistry – Level 4 – Chemical Changes and Structure Atomic structure and bonding related to properties of materials
The periodic table is a way to organise chemical elements There are around 100 elements.
(labels; metals, non-metals, groups, periods, halogens, noble gases, alkali metals, transition metals)
Group7 = halogens
period
Alkali
metals
group
metals
Transition metals
Non-metals
Group 8 = noble gases
Everything is made up of tiny particles called atoms These are made up of 3 smaller particles.
Name = electron
Charge = negative (-1)
Mass = 0
Found in = orbit
Name = neutron
Charge = 0
Mass = 1 (amu)
Found in = nucleus
Name = proton
Charge = positive (1+)
Mass = 1 (amu)
Found in = nucleus
The number of protons = the number of electrons, so the atom is neutral
Nuclide Notation
Mass number
= protons +
neutrons
X
Atomic
number =
number of
protons
Shows the
charge. If –ve
gained
electrons, if
+ve lost
electrons
Number of
atoms
Covalent
Non-metal + non-metal
Ionic
Non-metal + metal
Bond works by..
Shared pairs of electrons,
attracted to the positive
nuclei
Bond works by…
Ions forming (by electron
transfer), and attracting by
positive and negative charge
No
Low
(g) or (l) (few (s))
Yes (aq) and (l), No (s)
High
Normally (s)
Symbol (from
the periodic
table)
Conducts electricity
Melting/boiling point
State at room temperature
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There are 7 elements that form diatomics (means made of 2
atoms joined together)
I Have No Bright Or Clever Friends
HONClFIBr
Compound = two or more different elements joined together
Writing formulae
kind of formula
example
Elements
diatomic elements
compounds whose name
contains a number word
often end in -en, -on
or –ium;
(mono-; di-; tri-; etc)
iron; Fe
oxygen; O2
carbon dioxide;
CO2
copy from the
Periodic Table (add a 2 for diatomics)
do not use valency numbers
compounds ending in -ide
only two elements joined
together
(not hydroxide!)
sodium chloride;
NaCl
valency numbers from
the Periodic Table
1 2 3 4 5 6 7 8
1 2 3 4 3 2 1
compounds ending in
-ate or -ite
more than two elements
(often include oxygen)
sodium carbonate;
Na2(CO3)
data book for complex ions. Charge
gives the valency
compounds whose name
contains a roman number
(I); (II); (III); (IV)
copper (II) iodide;
CuI2
gives the valency number
of the transition metal
hydrocarbon compounds
ending in -ane or -ene,
hexene;
C6H12
carbon and hydrogen only
alkanes = C0H2n+2 alkenes = CnH2n
compounds containing a
sodium chloride;
only put in the charges if the ionic
Na+Clmetal and non-metal
formula is asked for
= Will have to use a Valency cross over to get the formula; Symbols, Valency, Cross, Cancel if you can, Write it down
ionic compounds
4 main shapes of molecules (add rest, diagrams and examples)
Linear
V-shaped / bent
pyramidal
Tetrahedral
e.g. Br2, HBr, CO2
e.g. CH4
e.g. H2O
e.g. NH3
To calculate the formula mass you need to multiple all the atoms in the formula by their RAM =relative atomic mass
e.g. CO2
= C = 1x 12
= 12
= O = 2 x 16
= 32
= 44
Check your key area statements. If not green you need to do more work!
Knowledge of the structure of the periodic table, groups and periods.
All matter is made of atoms. When a substance contains only one kind of atom it is known as an element. Atoms contain protons,
neutrons and electrons each with a specific charge, mass and position within the atom. The number of protons defines an element
and is known as the atomic number. The mass number of an atom is the number of protons plus neutrons. Atoms do not have an
electric charge and are said to be neutral.
Elements are arranged in the periodic table in order of increasing atomic number; elements with similar chemical properties are
grouped together. Elements can be categorised as metals and non-metals.
Compounds are substances formed when atoms of two or more elements join together. The name of a compound is derived from the
names of the elements from which it is formed with a suffix of -ide, -ite, or -ate. The ratio in which elements combine to form two
element compounds can be determined using valency rules. The chemical formula can also be determined from names with prefixes,
models or structures.
From the formula of a substance, its formula mass can be calculated using the Relative Formula Mass of the elements
A chemical reaction which can be described using word equations, can also be described using chemical symbol equations. Use of
state symbols in equations.
There are two types of compound. Covalent compounds form when non-metal atoms form covalent bonds by sharing their outer
electrons. Covalent compounds exist as molecules.
Ionic compounds form when metal atoms join to non-metal atoms by transferring electron(s) from the metal to the non-metal. The
resulting charged particles are called ions and an ionic bond is the attraction of the oppositely charged ions.
To be sure of the bonding present in a substance the properties must be tested.
Covalent compounds, made of molecules, have low melting and boiling points. As a result, they can be found in any state at room
temperature. Ionic compounds have high melting and boiling points. As a result, they are found in the solid state at room
temperature. Only ionic compounds can conduct electricity, they can only do this when molten or in solution.
You could use; check lists  mind maps  vocabulary lists  Summarised notes 
highlighted notes 
cue cards  past paper/practice questions  Other people testing you  Extra help after school
 BBC bitesize 
Quizlet flash cards  edmodo  other websites  (make sure you have a note of them if good)
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