Zusammenfassung der Ressource
Chemistry - Bonding Structure
& Properties of matter
- STRONG Chemical bonds
- IONIC BONDING
- Occurs in compounds
formed between METAL &
NON- METALS
- Particles produced are
oppositely charged ions
- Only electrons in outer shell
of METAL are TRANSFERRED
- Metals - LOSE ELECTRONS - become
+ly charged ions/ non metals GAIN
ELECTRONS- become -ly charged ions
- Ions produced by group 1+ 2
metals - and group 6+7 non
metals - has electronic
structure of NOBLE GAS ( group
0 - full outer shell)
- METALLIC BONDING
- Occurs in metallic
ELEMENTS & ALLOYS
- Atoms have
DELOCALISED
electrons
- FOUND ON THE OUTER SHELL- delocalised
electrons are free to move through WHOLE
STRUCTURE
- Metals are giant atomic
structures arranged in a
REGULAR pattern
- COVALENT BONDING
- Atoms SHARE PAIRS of
electrons- covalent bonds are
STRONG
- Occurs in NON metallic elements and
compounds of NON elements
- Covalent bonded structures - either small
molecule, polymers ( large molecules) or giant
covalent structures ( i.e diamond/silicon
dioxide)
- PROPERTIES OF SUBSTANCES
- Limitations of particle
theory-/ simple model -
NO FORCES / all
particles are shown as
SOLID SPHERE
- STATES SYMBOLS - (s) - solid / (l) liquid / (g) gas/ (aq)
aqueous solution - where the
solvent is water
- PROPERTIES OF IONIC COMPOUNDS
- Ionic compounds = regular structures/
lattices -have strong electrostatic forces
of attraction- in all directions = HIGH BPT
+ MPT- lots of energy needed to break
many strong bonds
- Ionic compounds CAN CONDUCT ELECTRICITY
when melted or dissolved in water- IONS MOVE
& CHARGE CAN FLOW
- PROPERTIES OF ALLOYS & METALS
- Pure metals = are ARRANGED
IN LAYERS- so can be BENT/
SHAPED
- But PURE METALS - too soft for
many uses - so are mixed with
OTHER metals - to make HARDER
ALLOYS
- Alloys have a DISORDERLY
ARRANGEMENT due to
different size of atoms
- METALS AS CONDUCTORS
- Metals - good electrical conductors -
delocalised electrons can carry electric charge
through metal
- Metals = good thermal conductors- energy
transferred via delocalised electrons
- Most metals - have HIGH BPT +
MPT - due to srong metallic bonds
- PROPERTIES OF GIANT COVALENT STRUCTURES
- Giant covalent structures = SOLIDS w/ VERY HIGH MPT
- Atoms are joined by strong covalent
bonds - that need to be overcome to
melt/boil substances- i.e carbon
allotropes ( silica/diamond)
- PROPERTIES OF POLYMERS
- Polymers - have v. LARGE molecules- the I.M.F(
INTERMOLECULAR FORCES) between polymers are
STRONG so substances are SOLID at room temp
- Atoms in polymers - linked to other
atoms via STRONG COVALENT BONDS
- PROPERTIES OF SMALL MOLECULES
- Substamces made up of SMALL
molecules - usually
GASES/LIQUIDS- low MPT +BPT
- Only have week I.M.F forces in between
molecules- these IMF and not covalent
bonds are broken when substance
melt/boils.
- Note : IMF increases with
SIZE of molecules - larger
molecules = higher mpt + bpt
- DON'T conduct ELECTRICITY -molecules don't have overall charge
- IONIC COMPOUNDS
- Ionic compound = GIANT
structure of ions ( shows IONIC
bonding)
- Held together via Strong ELECTROSTATIC
FORCES OF ATTRACTION between
oppositely charged ions
- Electrostatic forces - act is
ALL directions -forming a
LATTICE
- EMPIRICAL FORMULA
- EXAMPLE- Mg- 2e / Cl+2e -
gives the empirical formula
of MgCl2
- CARBON STRUCTURES/ ALLOTROPES
- DIAMOND - each carbon atoms
forms 4 COVALENT BONDS with
other carbon atoms - giant
covalent structure- Diamond is
VERY HARD/ HIGH MPT/
DOESN'T CONDUCT
ELECTRICITY
- GRAPHITE - carbon atom form 3
COVALENT bonds w/ 3 other
carbon atoms- form
HEXAGONAL rings - NO
COVELENT BONDS BETWEEN
LAYERS
- Graphite - has 1 DELOCALISED
ELECTRON from each carbon atom - so a
similar to metals in this way
- GRAPHENE - single layer of
graphite- used in
electronics/composites
- FULLERENES
- Fullerenes are molecules of carbon atoms w/
HOLLOW SHAPES- are made from hexagonal rings of
carbona toms - may contain ring with 5 or 7 carbon
atoms too - i.e Buckminister Fullerene (C60)- it is a
sphere
- CARBON NANOTUBES
- ARE CYLINDRICAL fullerenes - have a HIGH length to
diameter ratio - properties make them USEFUL for
nanotechology/materials/electronics/cosmetics/catalysts
- (NANO PARTICLES) Approx.1-100nm in diameter- so have
higher SA:VOL ratio - smaller quantities are needed for it
to be effective than normal size particles
- LIMITATIONS OF DOT +
CROSS/ BALL AND STICK
DIAGRAMS
- Ball + stick - pros - shows
charges on ions/ numer of atoms / 3D
arrangement/ cons - ions are
closer together/ false image of
bond direction
- Melting & freezing happen at mpt /
boiling and condensing happen at
bpt
- 3 STATES OF MATTER
- The energy required to change
states - depends on strength of
forces between particles and type
of bonding/strucutrw - stronger
bonging/forces = higher bpt &
mpt