Chemistry
IGCSE
, Everything is made of
bes
matter . The three states of matter a re solids , Liquids Phases
,
Arrangement & Motion :
Solids Liquids Gases
Solids
&
fixed ↑ i
:
regular shape fixed volume vibrate around fixed positions
, ,
- - 1
Liquids : no fixed shape Stake shape of containor) fixed volume flows , , ,
touching ↑
&
↑
-
Gases : no fixed shape ,
no fixed volume ,
can flow
·
Cannot be compressed
·
Cannot be compressed
·
Can be compressed
Solids have strong intermolecular forces Strong intermolecular forces RelativelyStrong forces .
Very weak intermolecular forces
Liquids have weak intermolecular forces
Gases have weak intermolecular forces < Solid
very
freezing melting
>
Liquid
Heating matter :
transferred to particles faster .
Condensing
Gas evaporatinga
T
-energy is the so
they move
Subliming
-
if sufficient energy is
provided they ,
overcome the strong forces of attraction & move from their positions (melting point)
Pressure :
Amount of force applied to the surface of a n object ove r a particular unit are a
"When increase the pressure of at fixed temperature volume decreases
you a
gas a ,
<
Pressure is
inversely proportional to volume (at a constant temperature
Separation :
Filtration : to re m ove insoluble solid from a liquid A solvent is a substance that dissolves a solute .
The filtered material is the residue the liquid is the filtrate A solute is a substance that is disolved in a solvent
,
A solution is a mixture of one or m o re solutes dissolved in a solvent
Crystalisation : to obtain a solid from its solution When water is the solvent the solution
,
is called
aqueous .
Distillation : a
way
to separate substances from a liquid mixture by boiling & then , condensing
·
The solubility of a substance in water is the amout that dissolves in
100g of water at that temperature .
Paper chromatography : to separate substances from a mixture
·
A solution is called saturated when it can dissolve m o re solute at that
to check whether a substance is
pure temperature
to identify substances in a mixture
distance from origin to dot
Rf :
distance from origin to solvent front
You can check if
something is pure by :
finding melting O boiling points
-
Carrying out
chromatography baseline
-
paper
You can increase
purity by :
Rinsing solid product with distilled water will impurities
·
wash some
a
away
Repeating separation technique
·
a
, ↑ S
Atoms are the smallest particles of matter that we cannot
Particle Relative Mass Relative Charge breakdown further by chemical means
Proton 1 1
+
Neutron 1 O
·
An element contains only one
type of atom
↳ A compound
Electron 2000 -
1 is made of different elements bonded together
subatomic particles A mixture contains different substances that are not bonded
together
Nucleon number :
protonst neutrons
Electronic configuration The period number tells how electron shells occupied Isotopes atoms of the element that have the # of protons but different # of neutrons
many
: a re
you : same same
The group number
tells the number of outer shell electrons They have the chemical properties
-
same
you
Unstable isotopes called radioisotopes
-
a re
All atoms relative to the carbon 12 atom
of
Signs
masses a re
of Chemical change :
·
The relative atomic m a ss
of element Ar is the m a ss of its isotopes compared to 12 the of carbon-12 atom
average New chemical
an m a ss a .
, , , -
substances a re formed
Ar latomic mass of the first isotope its % abundance) + latomic mass of second isotope its % abundance...
Energy taken out
during the reaction
-
is in or
given
The change usually difficult
-
is to reverse
OniC
Bonding Lovalent Bonding
·
Atoms bond with each other in order to obtain a full outer shell of electrons
Positive ions a re called cations A single covalent bond is
formed when two atoms share a
pair of electrons .
Negative ions a re called anions Non metals react with each other to form covalent compounds
The ionic bond is a
strong electrostatic attraction between ions of opposite charge .
·
In molecular covalent solids , the molecules aren't charged & the intermolecular forces a re weak
An compound forms when metal atoms lose their electrons to non-metal atoms Low
ionic .
melting
& boiling points
Compound ions a re ions formed from a
group of
bonded atoms (e .
g . NHT OH] NOz- Covalent compounds
, tend to be insoluble in water
In solids the forces between the
They
·
ionic
strong don't conduct electricity
·
,
ions are .
lonic compounds have high melting & boiling points : It takes a lot of heat to break the lattice
lonic compounds a re
usually soluble in water : water molecules separations from each other
lonic compounds can conduct electricity when molten or in solution
Giant Covalent Structures :
Diamond : a carbon atom forms covalent bonds to four others .
Graphite : each carbon atom bonds to three others
Very hard It has
-
held place by strong covalent bonds lattice structure . As the
in
layered layers have
: -
a
High melting point 3550 %
-
, weak intermolecular forces graphite is soft
Doesn't
High melting point
-
conduct
electricity
-
Rigid lattice structure
-
Conducts electricity 3 of carbon's electrons used
-
as are in bonds ,
so
each atom has one delocalised electron which can the current
carry
Silicon (IV) oxide : each silicon atom bonds to 4 atoms , Uses : as a lubricant for electrodes
oxygen ,
each
oxygen atom bonds
to 2 silicon atoms
-
Occurs
naturally as the mineral
quartz ,
in sand Allotropes :
multiple forms of the same element
Similar properties to diamond
IGCSE
, Everything is made of
bes
matter . The three states of matter a re solids , Liquids Phases
,
Arrangement & Motion :
Solids Liquids Gases
Solids
&
fixed ↑ i
:
regular shape fixed volume vibrate around fixed positions
, ,
- - 1
Liquids : no fixed shape Stake shape of containor) fixed volume flows , , ,
touching ↑
&
↑
-
Gases : no fixed shape ,
no fixed volume ,
can flow
·
Cannot be compressed
·
Cannot be compressed
·
Can be compressed
Solids have strong intermolecular forces Strong intermolecular forces RelativelyStrong forces .
Very weak intermolecular forces
Liquids have weak intermolecular forces
Gases have weak intermolecular forces < Solid
very
freezing melting
>
Liquid
Heating matter :
transferred to particles faster .
Condensing
Gas evaporatinga
T
-energy is the so
they move
Subliming
-
if sufficient energy is
provided they ,
overcome the strong forces of attraction & move from their positions (melting point)
Pressure :
Amount of force applied to the surface of a n object ove r a particular unit are a
"When increase the pressure of at fixed temperature volume decreases
you a
gas a ,
<
Pressure is
inversely proportional to volume (at a constant temperature
Separation :
Filtration : to re m ove insoluble solid from a liquid A solvent is a substance that dissolves a solute .
The filtered material is the residue the liquid is the filtrate A solute is a substance that is disolved in a solvent
,
A solution is a mixture of one or m o re solutes dissolved in a solvent
Crystalisation : to obtain a solid from its solution When water is the solvent the solution
,
is called
aqueous .
Distillation : a
way
to separate substances from a liquid mixture by boiling & then , condensing
·
The solubility of a substance in water is the amout that dissolves in
100g of water at that temperature .
Paper chromatography : to separate substances from a mixture
·
A solution is called saturated when it can dissolve m o re solute at that
to check whether a substance is
pure temperature
to identify substances in a mixture
distance from origin to dot
Rf :
distance from origin to solvent front
You can check if
something is pure by :
finding melting O boiling points
-
Carrying out
chromatography baseline
-
paper
You can increase
purity by :
Rinsing solid product with distilled water will impurities
·
wash some
a
away
Repeating separation technique
·
a
, ↑ S
Atoms are the smallest particles of matter that we cannot
Particle Relative Mass Relative Charge breakdown further by chemical means
Proton 1 1
+
Neutron 1 O
·
An element contains only one
type of atom
↳ A compound
Electron 2000 -
1 is made of different elements bonded together
subatomic particles A mixture contains different substances that are not bonded
together
Nucleon number :
protonst neutrons
Electronic configuration The period number tells how electron shells occupied Isotopes atoms of the element that have the # of protons but different # of neutrons
many
: a re
you : same same
The group number
tells the number of outer shell electrons They have the chemical properties
-
same
you
Unstable isotopes called radioisotopes
-
a re
All atoms relative to the carbon 12 atom
of
Signs
masses a re
of Chemical change :
·
The relative atomic m a ss
of element Ar is the m a ss of its isotopes compared to 12 the of carbon-12 atom
average New chemical
an m a ss a .
, , , -
substances a re formed
Ar latomic mass of the first isotope its % abundance) + latomic mass of second isotope its % abundance...
Energy taken out
during the reaction
-
is in or
given
The change usually difficult
-
is to reverse
OniC
Bonding Lovalent Bonding
·
Atoms bond with each other in order to obtain a full outer shell of electrons
Positive ions a re called cations A single covalent bond is
formed when two atoms share a
pair of electrons .
Negative ions a re called anions Non metals react with each other to form covalent compounds
The ionic bond is a
strong electrostatic attraction between ions of opposite charge .
·
In molecular covalent solids , the molecules aren't charged & the intermolecular forces a re weak
An compound forms when metal atoms lose their electrons to non-metal atoms Low
ionic .
melting
& boiling points
Compound ions a re ions formed from a
group of
bonded atoms (e .
g . NHT OH] NOz- Covalent compounds
, tend to be insoluble in water
In solids the forces between the
They
·
ionic
strong don't conduct electricity
·
,
ions are .
lonic compounds have high melting & boiling points : It takes a lot of heat to break the lattice
lonic compounds a re
usually soluble in water : water molecules separations from each other
lonic compounds can conduct electricity when molten or in solution
Giant Covalent Structures :
Diamond : a carbon atom forms covalent bonds to four others .
Graphite : each carbon atom bonds to three others
Very hard It has
-
held place by strong covalent bonds lattice structure . As the
in
layered layers have
: -
a
High melting point 3550 %
-
, weak intermolecular forces graphite is soft
Doesn't
High melting point
-
conduct
electricity
-
Rigid lattice structure
-
Conducts electricity 3 of carbon's electrons used
-
as are in bonds ,
so
each atom has one delocalised electron which can the current
carry
Silicon (IV) oxide : each silicon atom bonds to 4 atoms , Uses : as a lubricant for electrodes
oxygen ,
each
oxygen atom bonds
to 2 silicon atoms
-
Occurs
naturally as the mineral
quartz ,
in sand Allotropes :
multiple forms of the same element
Similar properties to diamond
