2 Atoms in the first
Shell 8 in the rest
E.G oxygen (8
Electrons) 2 on the
inner 6 on the next
Nucleus
Centre of an Atom
Contains Protons and Neutrons
Positive Charge +1
Negative Charge 0
Almost whole mass of
atom is concentrated here
Protons
Equal but opposite charges
Same number of
electrons and protons in
an atom
Elements
Only have 1 type of atom.
Each element has a different number of protons
Mixtures and
Compunds
Mixtures are easily seperated
Compounds are chemically bonded
properties of compounds are
different to original element
Naming Compounds 1) when two different
elements combine, the compounds name is
something-IDE 2) When three or more
elements combine, and one of them is
oxygen the compounds name is something
ATE
Chemical Reactions
Exothermic Reactions
Exothermic reactions give out heat to
surroundings and are shown by a rise in
temperature
Endothermic Reactions
Endothermic Reactions take
in heat from the surrounding,
and are shown by a fall in
temperatre
Periodic Table
Elements are put in order of
increasing atomic number
Dimitri Mendeleev made the table
of elements 1869
Gaps in his table predicted properties
of undiscovered elements
Periods
Rows are
called
Periods
Properties of elements change as you go
along a period
Groups
columns are called groups
properties of elements have similar
properties because they have the
same number of electrons in the
outer shell
properties of elements
gradually change as you go
down a group.
Common Substances and ions
Water (H2O)
Carbon Dioxide (CO2)
Carbon Monoxide (CO)
Sodium Hydroxide (naoh)
Ammonie (nh3)
Methane (ch4)
Sodium Hydroxide Carbonate (nahco3)
Positive Ions +1
Hydrogen (H)
Silver (AG)
all the first group of metals
Positive Ions +2
Iron (II) (FE)
Copper (II) (Cu)
Zinc (Zn)
All the
second
group of
metals
Positive ions +3
Aluminium (AL)
Ion (III)
Negative Ions -2
Oxide (O)
Sulphide (S)
Carbonate (CO3)
Sulphate (SO4)
Negative -1
Hydroxide (OH)
Nitrate (NO3)
All of the seventh
group of metals
Alkali Metals
(Group 1)
They have one electron on the outer shell and
want to get rid of it so they are very active
Elements further down the
group are more reactive
because the extra electron if
further from the nucleus.
Elements in group 1 are
more reactive as the atomic
number increases.
Alkali Metal + water -----> Metal Hydroxide + Hydrogen
The Halogens (Group 7)
Halogens are used in
toothpaste and non-stick
coasting on frying pans
On their own they are
poisonous
Chlorine is used to kill bacteria and is
used in bleach and swimming pools.
Iodine is used as an antiseptic
Aas the atomic number
increases the elements get
darker and have a higher boiling
point
the higher up group 7 the
element is, the more reactive
it is.
Halogens move around in pairs,
they are diatomic
Metals + Halogen = Salt (Metal Halide)
E.G Aluminium + Chlorine = Aluminium ChlorIDE
Fluorine (F) , Pale Yellow Gas.
Chlorine (CL), Pale Green Gas
Bromine (BR), Dark Red Liquid
Iodine (I) Purple Black Liquid
Astatine (AT) Grey-Black Solid
Noble Gases (Group O)
Colourless at room
temperature.
Inert full outer
shell so they
don't react
Neon is used in
electric discharge
tubes (red Light)
Helium neon and argon are
used in lasers
Helium is used in
airships and party
balloons
Argon is used in
Filament laps (Light
Bulbs)
Precipitates
Cobalt - Blue (turns grey when
left standing.
Copper - Pale Blue
Iron (II) Dark green (Turns
orange brown when left
standing)
Iron (III) - Orange
Brown
Manganese - Pale Brown
Nickel - Green
Zinc- White
Flame Test Colours
Lithium RED
Sodium INTENSE YELLOOW
Potassium LILAC
Calcium BRICK RED
Barium PALE GREEN
Copper GREEN BLUE
Acids and Bases.
Alkalis are Soluble
Citric Acid - Food Additive to
add sour taste to foods and
soft drinks
Ethanoic Acid - Acid in Vinegar.
Used in bottles and photographic
film and wood glue. diluted
ethanoic acid is used as a
descaling agent for kettle.
Hydrochloric acid - Plastics. used to process steel. Dilute
solutions used for cleaning, stomach acid
Phosphoric Acid -
production of petrol,
nylon and
detergents
Ammonia Fertilizers - used in
manufacturing of nitric acid and
sodium carbonate. Dilute
Ammonia used for cleaning.
Sodium Hydroxide - Caustic Soda.
Used to make Bleach and other
cleaning products E.G drain unblocker.
used in soap, paper and textile
manufacture