AQA AS Chemistry Unit 1

Chemistry 1 Revision

Atomic Structure

Atomic number of an atom is the number of protons within its nucleus - symbol X
Mass number of an atom is the number of sub-atomic particles in its nucleus, it is the
addition of neutrons and protons - symbol A
Isotopes are atoms that…

Graph of shows Relative Abundance of each ion on the Y axis and m/z ratio on the X axis
o This shows which isotopes are most common
o Using the information we can work out relative atomic mass
o The tallest peak is called the base peak
Relative Atomic Mass…

o Has an outer electron in the p sub-shell
Higher in energy than outer electron in
magnesium
o As a result less energy is needed to remove it
Sulphur
o Has an outer electron in the 3p sub shell
In phosphorous the 3p electrons are unpaired
In sulphur two of…

Elimination reactions involve removing a group of atoms from a molecule
Condensation reactions involve two molecules joining together to make a larger
molecule and a smaller one
C= n ÷ V
o C = concentration in mol dm-3
o N = amount of substance in mol
o V = volume…

o One of the atoms contributes both of the shared electrons
Shown by an arrow from the donating atom to the receiving atom
Shapes of molecules
o Linear
Bond angle = 180 degrees

o Trigonal planar
Bond angle = 120 degrees
o Tetrahedral
Bond angle = 109.5 degrees
o Trigonal…

Lone pair of electrons on the nitrogen, oxygen or fluorine atom
The single electron on the hydrogen is drawn away by the
electronegativity of the N, O and F atom
o The H atom is then strongly attracted to the lone pair of
electrons on the N, O or F…

Structural formula shows the number and type of each atom in a molecule and how they
are joined together
Displayed formula is the actual drawing of the alkane
Shortened structural formula is the CH3CH2CH2CH3 for example
Meth - 1 Eth -2 Prop - 3 But -4 Pent -5 Hex -…

Unburned hydrocarbons are oxidised to carbon dioxide and
water vapour
Acid rain is rain that is more acidic than normal
o Sulphur dioxide dissolves in water vapour to form sulphurous acid which is then
oxidised to form sulphuric acid
o Flue gases are waste gases from boilers and furnaces
Flue…