A LEVEL CHEMISTRY AQA PAPER 1
Exam Questions With Correct
Verified And Well Analyzed Answers
Graded A+
TOF steps
1) ionization
2) acceleration
3) ion drift
4) detection
5) analysis
Electron impact
Sample vaporized and electron gun fires high energy electrons at it
which knock off 1 electron from each particle, making them 1+ ions
NB- can knock off more than one e or break molecular ion
electrospray ionization
Sample dissolved in volatile solvent then injected through needle to
give fine mist which is attached to positive end of high voltage power
supply, particles gain proton
NB- Mr. of substance is actually one less than shown due to extra H+
Acceleration (TOF)
positive ions accelerated using electric field so they all have the same
kinetic energy
Ion drift (TOF)
particles with small mass have larger velocity do ions start to
separate with lightest ions reaching detector first
Detection (TOF)
, positive ions hit negatively charged plate and gain an electron which
forms a current, the larger the current the higher the abundance
Analysis (TOF)
-computer uses data to produce mass spectrum which shows mass m
/ charge z ratio
-Mr. or ar is furthest right peak (small peaks larger than mr are due to
isotopes)
-may be large peaks at lower mr due to fragmentation
Electron spin
Property of electron (CW or ACW)
Represented by up and down arrows
Orbitals
Defined regions of space around nucleus where electrons most likely
to be found, each orbital holds 2 electrons
Hund's Rule
Electrons prefer to occupy orbitals on their own and only pair up
when no empty or bait ask of same energy are available
Electron configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
exceptions to electron configuration
chromium and copper, only take one electron in 4s orbital
Why does ionization energy decrease down a group?
Atoms get bigger so electrons further away from nucleus, greater
shielding
Why does ionization energy increase across a period?
Atoms get smaller, nuclear charge increases, similar shielding
Dip in ionisation energy groups 2-3
Electrons take up higher orbital (s to p) which makes ionisation
energy lower as higher orbitals have higher energy
Exam Questions With Correct
Verified And Well Analyzed Answers
Graded A+
TOF steps
1) ionization
2) acceleration
3) ion drift
4) detection
5) analysis
Electron impact
Sample vaporized and electron gun fires high energy electrons at it
which knock off 1 electron from each particle, making them 1+ ions
NB- can knock off more than one e or break molecular ion
electrospray ionization
Sample dissolved in volatile solvent then injected through needle to
give fine mist which is attached to positive end of high voltage power
supply, particles gain proton
NB- Mr. of substance is actually one less than shown due to extra H+
Acceleration (TOF)
positive ions accelerated using electric field so they all have the same
kinetic energy
Ion drift (TOF)
particles with small mass have larger velocity do ions start to
separate with lightest ions reaching detector first
Detection (TOF)
, positive ions hit negatively charged plate and gain an electron which
forms a current, the larger the current the higher the abundance
Analysis (TOF)
-computer uses data to produce mass spectrum which shows mass m
/ charge z ratio
-Mr. or ar is furthest right peak (small peaks larger than mr are due to
isotopes)
-may be large peaks at lower mr due to fragmentation
Electron spin
Property of electron (CW or ACW)
Represented by up and down arrows
Orbitals
Defined regions of space around nucleus where electrons most likely
to be found, each orbital holds 2 electrons
Hund's Rule
Electrons prefer to occupy orbitals on their own and only pair up
when no empty or bait ask of same energy are available
Electron configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
exceptions to electron configuration
chromium and copper, only take one electron in 4s orbital
Why does ionization energy decrease down a group?
Atoms get bigger so electrons further away from nucleus, greater
shielding
Why does ionization energy increase across a period?
Atoms get smaller, nuclear charge increases, similar shielding
Dip in ionisation energy groups 2-3
Electrons take up higher orbital (s to p) which makes ionisation
energy lower as higher orbitals have higher energy
