VCE chemistry unit 1

isotopes

variants of an element which have the same atomic number but a different number of neutrons in there nuclei/different mass number

metallic character

Degree to which an element is shiny and can conduct electricity (decreases across a period, increases down a group)

s block

groups 1-2

d block

groups 3-12 = transition metals

p block

groups 13-18,

f block

lanthanoids and actinoids

core charge

number of protons - inner shell electrons (increase across a period, decrease down a group)

atomic radius

the distance from the centre of an atom to the valence electrons (decreases across a period, increases down a group)

periodicity

characteristics of elements in a period, they are the trends in the periodic table

electronegativity

is the ability of an element to attract shared electrons to itself (increases across a period, decreases down a group)

first ionisation energy

energy required to remove first valence electrons from an atom (increases across a period, decreases down a group)

metallic bonding

metals have low ionisation energy so therefore require a small amount of energy is required to remove valence electrons from atoms

properties of metals

imelleable - ability to be hammered/ put under pressure to not break

ductile - can be stretched into thin wire and not break

electric conductivity - ability to allow an electric current to flow through

heat conductivity - when a piece of metal absorbs heat the rise in temperature cause an increase kinetic energy of delocilaised electrons and cations

how many periods is there?

7

how many groups is there?

18

covalent bonding

involves the sharing of electrons between elements

ionic bonding

metal atoms that donate valence electrons to non metal atoms to form cations & anions

octect rule

rule saying that an atom is more stable when they have 8 elctrons on their valence shell

dispersion forces

weakest intermolecular force to hold molecules together, occurs because electrons keep moving around

dipole-dipole attraction

stronger than dispersion forces because of permanent dipole-dipole movements (polar), occurs when there is a significant difference in electronegativity between atoms of molecules

hydrogen bonding

strongest form of dipole-dipole attraction

properties of ionic bonding

hardness = ionic bonds between positive and negative ions form a crystal lattice structure

brittleness = the repulsive force between ions of like charges is strong enough to shatter the lattice

melting point = a lot of energy is required to break the bonds because of the strong crystal lattice structure = high-melting point

conductivity = ability of iconic compounds to conduct electricity (depends on physical state)

monatomic ions

ions made of 1 atom

iconic compounds that are neutral = don't have overall charge

polyatomic ions

made of a group of atoms covalently bonded together

overall charge is cumulative charge of each atom

relative atomic mass formula

Ar= (relative abundance x atomic mass)+( relative abundance x atomic mass).../100

avogadros constant

N = n x Na

N= total number of particles

n = number of moles

Na= 6.02x10^23 (avogadros constant)

mass calculations involving the mole

n = m/M

n = number of moles

m = mass

M = molar mass

molar mass

M = (atomic mass x number of compound) + (atomic mass x number of compound) ....

percentage composition

= (mass of element in 1 mol/molar mass) x 100

empirical formula

1. determine mass of each compound

2. calculate the amount in mol (n=m/M)

3. divide the amount of each element in mol by the lowest mol calculated

molecular formula

1. determine empirical formula + find molar mass

2. = molar mass MF/molar mass of EF

3. multiply empirical formula by answer

alkanes

singe carbon to carbon bonds

saturated

general formula = CnH2n+2

alkenes

contains one of more double carbon to carbon chains

unsaturated

general formula = CnH2n

haloalkanes

has a halogen atom (bromine, fluorine chlorine, iodine)

alcohols

has a hydroxyl atom (OH), '-ol'

carboxylic acids

has a carboxyl group (COOH), '-ohic acid'

alkyl

branched hydrocarbons, '-yl'

monomers

are a unit

polymers

are covalent molecule substances made of many repeating monomers

addition polymerisation

adding many monomers to make a polymer

condensation polymerisation

a reaction in which monomers are linked together into a polymer with the release of a small molecule, such as water, as a by-product

formation of addition polymers

polymers are highly modifiable and many different polymers posses their own unique properties

e.g. light & strong, durable, flammable

non polar monomers

are held together with weak dispersion forces

polar monomers

are held together by either dipole dipole interactions or hydrogen bonds = more harder and rigid

polymerisation

takes place at high temperatures and pressure, it prevents polymers from forming linear chains

circular economy

continues circle that focuses on optimal use and re-use of resources

linear economy

operates on a take and make dispose model, making use of resources to produce products that will be discarded after use

ammonium

NH4+

silver

Ag+

calcium

Ca2+

barium

Ba2+

strontium

Sr2+

aluminium

Al3+

bromide

Br-

hydroxide

OH-

nitrate

NO3-

hydrogen carbonate

HCO3-

hydride

H-

'ide'

a negatively charged ion that is formed by a single atom

'ite'

one less oxygen then 'ate'

'ate'

high oxidation state

carbonate

CO3^2-

sulfate

SO4^2-

sulfide

S2-

oxide

O2-

nitride

N3-

phosphate

PO4^3-

what plastics are made from fossil fuels?

HDPE, LDPE, PP

corn, sugarcane

renewable feedstock for the production of bio ethanol

disadvantage of bioethanol

expensive, high water requirement

curde oil

non renewable feedstock for the production of useful organic compounds

everyday useful organic compound

alcohol, rubber band, detergent

thermoplastic

can be remoulded with heat

thermoset

have cross links = covalent bonds, presence of cross links restrict movement making it hard and rigid

polar

functional group + organic compound

non-polar

organic compound