2457485
Edexcel
Additional
Science
Chemistry
Topics 1+2
- The Atom
- Nucleus- in the
centre; it contains
protons and
neutrons.
- Electrons- they move
around the nucleus;
they have a negative
charge; they occupy
shells / energy levels.
The first energy levels
holds 2, every other
holds 8. A full shell
equates to 8
electrons. (the second
shell onwards)
- Electrons- they move
around the nucleus;
they have a negative
charge; they occupy
shells / energy levels.
The first energy levels
holds 2, every other
holds 8. A full shell
equates to 8
electrons. (the second
shell onwards)
- Atomic Number-
tells you the number
of protons which is
equal to the number
of electrons.
- Mass Number- the
total number of
protons and
neutrons combined.
Mass number-
Atomic Number=
no. of neutrons
- Proton
- 1
- +1
- +1
- 1
- Neutron
- 1
- 0
- 0
- 1
- Electron
- 1/2000
- Relative
Mass
- -!
- Relative
Charge
- Relative
Charge
- Relative
Mass
- 1/2000
- Proton
- Mass Number- the
total number of
protons and
neutrons combined.
Mass number-
Atomic Number=
no. of neutrons
- Nucleus- in the
centre; it contains
protons and
neutrons.
- Isotopes
- isotopes- the different
atoms of the same
element which have the
same number of
protons but different
numbers of neutrons.
(different mass
numbers)
- e.g. isotopes include
Carbon 12/14 and
Chlorine 35/37
- Relative Atomic Mass
of Isotopes: (% of
isotope 1 × mass of
isotope 1) + (% of isotope
2 × mass of isotope 2) ÷
100
- Relative Atomic Mass
of Isotopes: (% of
isotope 1 × mass of
isotope 1) + (% of isotope
2 × mass of isotope 2) ÷
100
- e.g. isotopes include
Carbon 12/14 and
Chlorine 35/37
- Organ-
isation
of The
Periodic
Table
pt.1
- 1800s- scientists
didnt know about
the structure of
atoms, so ordered
them in atomic
mass
- 1800s- scientists
didnt know about
the structure of
atoms, so ordered
them in atomic
mass
- isotopes- the different
atoms of the same
element which have the
same number of
protons but different
numbers of neutrons.
(different mass
numbers)
- Organisation of the
Periodic Table pt.2
- 1869- Dmitri
Mendeleev
ordered elements
in groups,
according to their
properties. This
left gaps; the
gaps predicted
new elements
- Metals and non
metals are on
opposite sides of
the table; metals
-left, non metals-
right
- Periods- these run
across the periodic
table in rows; the
elements are
increasing in atomic
number. the row
number that the
element is in
corresponds to
number of energy
levels/ shells the
element has. e.g. the
elements in period 3
have 3 energy
levels/shells.
- Groups- these are
columns that run
down the periodic
table; elements in
these groups have
similar properties
because they have
the same no. of
electrons on their
outer shell. the group
no. equals the no. of
electrons on their
outer shell.
- Groups- these are
columns that run
down the periodic
table; elements in
these groups have
similar properties
because they have
the same no. of
electrons on their
outer shell. the group
no. equals the no. of
electrons on their
outer shell.
- Periods- these run
across the periodic
table in rows; the
elements are
increasing in atomic
number. the row
number that the
element is in
corresponds to
number of energy
levels/ shells the
element has. e.g. the
elements in period 3
have 3 energy
levels/shells.
- 1869- Dmitri
Mendeleev
ordered elements
in groups,
according to their
properties. This
left gaps; the
gaps predicted
new elements
- Ionic Bonding
- in ionic bonding electrons are
transferred to form positively or
negatively charged atoms called
ions, because of the attraction of
opposite charges + and -, the ions
are strongly attracted
- A shell with 1/2/3
electrons will be
looking forward
to lose 1 or 2. or 3
this is because
it's quicker than
trying to gain 7
or 6.
- A shell with
6,5 or 7
electrons
will be
looking to
gain 1 or 2
electrons
because it's
quicker and
easier than
losing 5/6/7.
- PROPERTIES
- ionic bonds
produce
compounds with
similar
structures; the
ions form a
closely packed
regular lattice
arrangement
- They have high
melting points, due
to the very strong
bonds between the
ions and
electrostatic forces
of attraction; it
takes a lot of
energy to break
these bonds
- They
conduct
electricity
when
aqueous of
molten.
when
dissolved the
ions
separate
and are all
free to move
so they'll
carry electric
current..
- They
conduct
electricity
when
aqueous of
molten.
when
dissolved the
ions
separate
and are all
free to move
so they'll
carry electric
current..
- They have high
melting points, due
to the very strong
bonds between the
ions and
electrostatic forces
of attraction; it
takes a lot of
energy to break
these bonds
- ionic bonds
produce
compounds with
similar
structures; the
ions form a
closely packed
regular lattice
arrangement
- PROPERTIES
- A shell with
6,5 or 7
electrons
will be
looking to
gain 1 or 2
electrons
because it's
quicker and
easier than
losing 5/6/7.
- A shell with 1/2/3
electrons will be
looking forward
to lose 1 or 2. or 3
this is because
it's quicker than
trying to gain 7
or 6.
- in ionic bonding electrons are
transferred to form positively or
negatively charged atoms called
ions, because of the attraction of
opposite charges + and -, the ions
are strongly attracted
- Dot and Cross Diagrams
- Dot and Cross diagrams show
where electrons have moved during
ionic bonding and the charges that
elements have as a result.
- if elements
lose electrons
they gain a
positive charge,
the number of
electrons they
lose will go
after the
charge sign. e.g
calcium has 2
electrons on its
last energy
level, it ionically
bonds and
loses 2. so it
has a charge of
+2
- if elements
gains electrons
they gain a
negative
charge, the
number of
electrons they
gaim will go
after the
charge sign. e.g
chlorine has 7
electrons on its
last energy
level, it ionically
bonds and
gains 1. so it
has a charge of
+1
- if elements
gains electrons
they gain a
negative
charge, the
number of
electrons they
gaim will go
after the
charge sign. e.g
chlorine has 7
electrons on its
last energy
level, it ionically
bonds and
gains 1. so it
has a charge of
+1
- Arrows
show where
the electron
moves
- the new
electron
configurations
are drawn
with their
charges
- the new
electron
configurations
are drawn
with their
charges
- if elements
lose electrons
they gain a
positive charge,
the number of
electrons they
lose will go
after the
charge sign. e.g
calcium has 2
electrons on its
last energy
level, it ionically
bonds and
loses 2. so it
has a charge of
+2
- Dot and Cross diagrams show
where electrons have moved during
ionic bonding and the charges that
elements have as a result.
- Insoluble
Salts
- All
nitrates
are
soluble
- All
chlorides
are
soluble
expect
silver
and lead
- All
sulfates
are
soluble
expect
barium,
calcium
and lead
- All
carbonates
and
hydroxides
are
INSOLUBLE
except
SODIUM,
AMMONIUM
and
POTASSIUM
- All
carbonates
and
hydroxides
are
INSOLUBLE
except
SODIUM,
AMMONIUM
and
POTASSIUM
- All
sulfates
are
soluble
expect
barium,
calcium
and lead
- All
chlorides
are
soluble
expect
silver
and lead
- All
nitrates
are
soluble
- Precipitation
Reactions
- 1. add 1
spatula of
compound to a
test tube, fill
with distilled
water and
shake
thoroughly. do
the same with
the other
compound
- 2. tip the 2
solutions into
a beaker and
give it a stir
to ensure it's
all mixed
together. the
precipitate
will appear as
the 2
solutions
react.
- 3. put a
folded piece of
filter paper
into a filter
funnel. put the
funnel on a
conical flask
- 4. pour the
content of
the beaker
into the
middle of the
filter paper
- 5. swill out
the beaker
with more
distilled water
and tip it onto
the paper
- 6. rinse the
content of
the filter
paper with
distilled
water to
make sure
all of the
soluble
product from
the reaction
has washed
away and all
that remains
is the
precipitate
- 7.scrape of
the
precipitate
and put it on
fresh filter
paper and
leave to dry
- 7.scrape of
the
precipitate
and put it on
fresh filter
paper and
leave to dry
- 6. rinse the
content of
the filter
paper with
distilled
water to
make sure
all of the
soluble
product from
the reaction
has washed
away and all
that remains
is the
precipitate
- 5. swill out
the beaker
with more
distilled water
and tip it onto
the paper
- 4. pour the
content of
the beaker
into the
middle of the
filter paper
- 3. put a
folded piece of
filter paper
into a filter
funnel. put the
funnel on a
conical flask
- 2. tip the 2
solutions into
a beaker and
give it a stir
to ensure it's
all mixed
together. the
precipitate
will appear as
the 2
solutions
react.
- how to get a
pure dry
precipiate
- 1. add 1
spatula of
compound to a
test tube, fill
with distilled
water and
shake
thoroughly. do
the same with
the other
compound
- Barium
Sulfate
- Barium
sulfate is
an
insoluble
salt used
in x-rays.
- normally only bones show up on
x-rays, BaSO4 is opaque so when drunk
it shows up in the gut and any
problems like blockages can be seen
- BaSO4 salts are toxic but can be safely
drunk because they're insoluble; they
wont pass into the bloodstream. it just
passes through the body.
- BaSO4 salts are toxic but can be safely
drunk because they're insoluble; they
wont pass into the bloodstream. it just
passes through the body.
- normally only bones show up on
x-rays, BaSO4 is opaque so when drunk
it shows up in the gut and any
problems like blockages can be seen
- Barium
sulfate is
an
insoluble
salt used
in x-rays.
- FLAME
TEST
- Sodium-
Yellow/ Orange
- Potassium-
Lilac
- Calcium- Red
- Copper- Blue/Green
- Copper- Blue/Green
- Calcium- Red
- Potassium-
Lilac
- 1. dip a wire loop into HCL
and rinse it off with water
to ensure it is clean
- 2. dip the wire loop into the
compound sample and put it
into the blue flame of a
bunsen burner
- this method can be used for
both solution and solid
forms of compounds. if doing
solids, dip in HCL before to
make sure the compound
sticks.
- this method can be used for
both solution and solid
forms of compounds. if doing
solids, dip in HCL before to
make sure the compound
sticks.
- 2. dip the wire loop into the
compound sample and put it
into the blue flame of a
bunsen burner
- Sodium-
Yellow/ Orange
- Testing for Ions
- Carbonates- add the suspected ions to
dilute HCL. carbonates react with acid to
make CO2. Pipe the gas created from the
reaction into a test tube full of
limewater. if carbonate ions are present
it will go cloudy because of the CO2.
- Sulfates- to test for sulfate ions add
dilute HCL followed by a barium
chloride solution. if there are sulfate
ions a white precipitate will appear:
barium sulfate
- Chloride- to test for chloride ions add
dilute nitric acid followed by a silver
nitrate solution. if chloride ions are
present, a white precipitate will form:
silver chloride
- Chloride- to test for chloride ions add
dilute nitric acid followed by a silver
nitrate solution. if chloride ions are
present, a white precipitate will form:
silver chloride
- Sulfates- to test for sulfate ions add
dilute HCL followed by a barium
chloride solution. if there are sulfate
ions a white precipitate will appear:
barium sulfate
- Carbonates- add the suspected ions to
dilute HCL. carbonates react with acid to
make CO2. Pipe the gas created from the
reaction into a test tube full of
limewater. if carbonate ions are present
it will go cloudy because of the CO2.
- Spectro-
scopy
- using light emitted by
elements in a heated sample
to identify elements
- using light emitted by
elements in a heated sample
to identify elements
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