VCE Chemistry Unit 1 (copy)

s sub-shell

1 orbital and max 2 electrons

p sub-shell

3 orbitals and max 6 electrons

d sub-shell

5 orbitals and max 10 electrons

f sub-shell

7 orbitals and max 14 electrons

copper and chromium exception

want either 5 or 10 electrons in 3d sub-shell so take one from 4s sub-shell

sub-shell arrangement

metallic bonding

bonding between two metals

properties of metallic bonding

- conduct electricity
- shiny (lustrous)
- high mp
- generally dense
- reflect light
- malleable and ductile

high boiling temperature (metallic)

due to strong electrostatic forces between cations and delocalised electrons holding lattice together

conduct electricity (metallic)

electrons move towards a positive electrode in a circuit

malleable and ductile (metallic)

when forces cause metal ions to move past each other and layers of ions are still held together by electrons

density (metallic)

because lattice of cations is so tightly packed together

reflect light (metallic)

light bounces off surface electrons to give a shiny appearance

metallic bonding limitations

- heavy metal mercury (liquid at room temp.)
- differences in electrical conductivity
- magnetic properties

lattice of cations

3D crystal lattice filled with protons and delocalised negative electrons that is held together by electrostatic forces

alloys

compounds of metals that are stronger, corrosion resistant and made of two or more metals with metals of similar sizes and lattice layers harder to move

metal reactivity

group 1 more reactive than group 2 and as elements go down groups reactivity increases because valence electrons are further away. Metals are more reactive than water

modifying metals

- work hardening
- annealing
- quenching
- tempering
- coating

work hardening

pushing metal crystals together as small crystals = less movement and harder material

annealing

heating metals and slowly cooling as it makes larger crystals as softer = more ductile

quenching

heating metals but rapidly cooling as it makes smaller crystals and harder but more brittle

tempering

heating to a lower temperature and slowly cooling to make medium crystals, so hard but less brittle

coating

coating metals to prevent corrosion

nanomaterials

- nanoparticles
- nanorods
- nanowires

nanomaterial applications

- wound dressings
- medicine
- sunscreen
- electronics
- superconductors

ionic bonding

bonding metal and non-metal together with high bp and mp, solid at room temp., hard and brittle, only conduct in liquid state, strong intramolecular forces

masses of particles

all masses are relative (in chemistry) with the standard reference point for all other atoms being carbon-12

isotope

same element but with a different mass (different nº of neutrons

relative isotopic mass

the mass of an atom of the isotope relative to carbon-12 mass (symbol = IR) with the value coming from a mass spectrometer

mass spectrometer

a machine that can measure the number of isotopes in a given sample and the abundance of them

relative isotopic abundance

the abundance of certain isotopes given in a percentage

relative atomic mass

the average mass of an element as most elements have many isotopes (symbol Ar)

Ar (relative atomic mass)

(relative isotopic mass x abundance%)+(..)+(..)÷100

relative molecular mass

mass of a molecule relative to carbon-12 but not referring to one element. Is equal to the sum of all Ar of every atom (symbol Mr)

relative formula mass

same as Mr except for the compounds that aren't non-metals (symbol Fr)

mol

a unit used by chemists to count atoms, ions/molecules (symbol N)

avogardos number

1 mol of any substance contains 6.02x10^23 particles (symbol Na)

n

mol (amount of substance)

Na

avogardos number

N

actual number of particles

molar mass

the mass in grams of one mole of a substance

compound

made up of 2 or more different atoms

percentage compound

tells you the percentage of different elements in a compound

empirical formula

the simplest whole number ratio of each atom in a molecule

molecular formula

gives the actual amount of atoms in a compound/molecule and can be the same or similar to empirical

non-metal properties

- low mp and bp
- often not solid
- soft when solid
- no electrical conductivity

intramolecular bond

bonding within a molecule which is strong

intermolecular bond

bonding between molecules which is weak

covalent bonding

sharing electrons and not transferring

lone pairs

the valence electrons not involved in bonding

molecular compound

molecular bond between different types of atoms

polyatomic molecule

more than two atoms in a molecule

shape of molecules

determine physical properties and is determined by VSEPR (valence shell electron pair repulsion)

VSEPR

the lone pairs repel each other and arrange themselves as far away from each other as possible which determines the shape and takes bonds and lone pairs into consideration

tetrahedral

pyramidal

v-shaped or bent

intermolecular forces

size, shape and polarity determine types of forces
- dipole-dipole
- hydrogen bonding
- dispersion forces

dipole-dipole forces

only in polar molecules and relatively weak since particle charges are small. More polar = stronger bonds due to the difference in E.N. and higher mp and bp

hydrogen bonding

type of dipole-dipole that occurs only between H and O, F or N. Is stronger than dipole-dipole but weaker than others with high mp + bp

dispersion forces

the only type of non-polar bondings but present in polar which is caused by temporary dipoles due to the random movement of electrons

organic chemistry

all non-metal chemistry

hydrocarbon

compound made of hydrogen and carbon

alkenes

has at least 1 double bond and doesn't dissolve in water, is non-polar and unsaturated. Stem name + 'ene'

addition reactions

part or all of the reactant becomes added to the alkene breaking the double bond and combusting

alkynes

has at least 1 triple bond and is unsaturated and structural isomers exist for 3C or above which increase/decrease mp + bp. Stem name + 'yne'

alkane

only single bonds which in non-polar, doesn't dissolve, relatively unreactive and has weak dispersion forces. Stem name + 'ane'

meth

1 carbon

eth

2 carbon

prop

3 carbon

but

4 carbon

pent

5 carbon

hex

6 carbon

hept

7 carbon

oct

8 carbon

non

9 carbon

dec

10 carbon

molecular formula

structural formula

structural isomers

the same formula but a different structure

alcohols

when OH bonds to a carbon chain, hydrogen bonding can occur and mp + bp are higher. Stem name + 'ol'

carboxylic acids

carboxyl group with OOH added to a carbon chain which is more polar like an organic acid and can only be added at the end. Stem name + 'anonic acid'

esters

formed by a reaction between alcohol and carboxylic acid in the presence of sulfuric acid (catalyst) which forms artificial flavours and colours with condensation as a byproduct