Zusammenfassung der Ressource
VCE Chemistry Unit 1
- Elements and The Periodic Table
- Forms of the Periodic Table
- Medeleer's Periodic table - Arranged in order of increasing
atomic mass and similar chemical properties
- The modern periodic table - Elements arranafed
in increasing atomic number (no. of protons)
- Trends in the Periodic Table
- Atomic radius - Decrease
across, Increase down
- Electronegativity -
Increase across, Decrease
down
- Ionisation energy -
Increase across,
decrease down
- Reactivity of metals -
increase down (easier to
loose electrons)
- Reactivity of non-metals -
Decrease down (harder
to loose electrons)
- Reactions are
transfers of
electrons
- Atomic radius =
distance from nucleus
to valence electrons
- Electronegativity =
atoms ability to attract
electrons to itself
- Schrondinger
model = s,p,d,f
- Metals
- Metallic
bonding
- Properties of
metals
- Har and high boiling point
- Strong electrostatic
attraction forces
- Conductive
- Free moving delocalised electrons
will move to a positve electrode
- Ductility and
malleability
- Force applied causes
metal ions to side past
each other
- Lustre
- Conduction of heat
- Metal structure
- Smaller crystals = harder metal
- Smaller crystals = more brittle
- Structure can be altered
- Workhardening = working cold
metals causes a rearrangment
of crystal grains
- Smaller crystals = harder and more
brittle
- Alloying = metals melted and
mixed with another substance
they are generally harder with a
lower melting point
- Substitutional = fairly similar sized
cations formed by elements with
similar properties to the main metal
- Interstitial = smaller portion of
signifcantly smaller atoms
added to the main metal
- Heat treatment = casting moltern
metal solidifies crystals grow,
individual crystals = grains
- Annealing = heat and cool
slowly (larger crystals)
- Quenching = heated and cooled
quickly (tiny crystals)
- Tempering = low heating and slow
cooling (intermediate crystals)
- Delocalised elctrons are located in
spoecific places therfore they are
unable to jump crystals during any
manipulation
- Ionic bonding = transfer of elctrons
resulting in cations and anions
electrostatically attracted forming ionic
bonds
- Common
properties
- Brittleness
- Hardness
- High melting point
- Difference in electrical
conductivity in solid vs liquid shape
- Formation of
crystals
- Cooling rate
- Concentration of solution
- Hydrated ionic compounds = water
molecules trapped within the ionic lattice
- Covalent bonding = bonding where
both atoms share electrons to
complete their outershells
- Molecular representation
- VSEPR to determine the shape of
molecules
- Valence shell electron pair
repulsion (VSEPR) = Outer
shell electron pairs
mutually repel due to their
negative charge and adopt
possitiions as fair from each
other as possible
- Lone pairs repel slightly more
than bonding pairs
- Double/triple bonds
are treated as a
single bond in this
model as they must
stay in the same
location they don't
repel
- Electronegetivitiy and
polatity
- Polar bond = uneven distribution of
charge resulting in one atom being
more negative than the other
- Intramolecular forces = forces that
exist between different molecules
- Intermolecular forces = weak , the strength
of the two forms of attraction determines
different properties of covalent compounds
- Dispersion force = result of attraction between
temporary dipoles. These can be random
fluctuations in the distribution of electrons
- Dipole-Dipole force = occur due to
permanent dipole
- Increased polarity the stronger
the dipole-dipole forces
- Result of the electrostatic attraction
between the polar ends of polar molecfules
- Hydrogen bonding= stronger dipole-dipole forces
developed when a FON bonds with hydrogen
- Carbon lattices
- Allotropes = different forms of the same elements