AS Chemistry Unit 1 AQA

Isotope

Same proton number different neutron number

Mass spectormeter :

1- ionisation- electron gun

2-acceleration-negatively charged plates

3- deflection - magnetic feild

4- detection- at detector produces mass spectrum

3 main energy subshells  shells

S  P  D  subshells

2 e- in same orbital have opposite spins

4s filled before 3d

Ionisation Energy

first ionisation energy is the energy required to remove one mole of electrons from an atom in the gaseous state

measured in kjmol -1

Trends - drop in al and s due to subshell arrangement

relative atomic mass

ram= average mass of one atom of element / 1/12th of mass of 12C

relative molecular mass= average mass of molecule/ 1/12th of 12 C

Ideal gas equation - PV=nRT p=pa  t=k v=m

Empirical and molecular formula

simplest ratio -3 simple steps to work it out 

-mass/mr

-divide by smallest number put into ratio

molecular is mass of molecule/empirical formula

number of moles = mass/mr

concentration=moles/volume in dm3

moles in solution =m*v/1000

ionic equations

remove spectator ions to get the overall reaction

% Atom economy= mass of desired product/ total mass of reactants * 100

% Yeild of a reaction=number of moles of product/theoretical max yeild possible * 100

Ionic Bonding- between metals and non metals -  transfer of electrons - 2 charged particles produced - attraction via electrostatic forces on the compound

always exist as a lattice of alternating charged particles

solid at room temp - giant structures - conduct electricity when molten or dissolved

brittle and shatter easily due to the alternatingly charged ions

Mettalic Bonding- between metals- sea of delocalised electrons so able to carry charge

greater charge = stronger metal

smaller ion = stronger metal

malleable(beaten into shape) and ductile (pulled into wires)

high melting points