AQA A LEVEL CHEMISTRY PAPER 1
Study online at https://quizlet.com/_71y27d
1. TOF steps 1) ionisation
2) acceleration
3) ion drift
4) detection
5) analysis
2. Electron impact Sample vaporised 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
3. 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+
4. Acceleration (TOF) positive ions accelerated using electric field so they all have the same
kinetic energy
5. Ion drift (TOF) particles with small mass have larger velocity do ions start to sepa-
rate with lightest ions reaching detector first
6. Detection (TOF) positive ions hit negatively charged plate and gain an electron which
forms a current, the larger the current the higher the abundance
7. 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
8. Electron spin Property of electron (CW or ACW)
Represented by up and down arrows
1/8
, AQA A LEVEL CHEMISTRY PAPER 1
Study online at https://quizlet.com/_71y27d
9. Orbitals Defined regions of space around nucleus where electrons most
likely to be found, each orbital holds 2 electrons
10. 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
11. Electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
12. exceptions to electron con- chromium and copper, only take one electron in 4s orbital
figuration
13. Why does ionization ener- Atoms get bigger so electrons further away from nucleus, greater
gy decrease down a group? shielding
14. Why does ionization ener- Atoms get smaller, nuclear charge increases, similar shielding
gy increase across a peri-
od?
15. Dip in ionisation energy Electrons take up higher orbital (s to p) which makes ionisation
groups 2-3 energy lower as higher orbitals have higher energy
16. Dip in ionisation energy Electron- electron repulsion in orbital makes electron easier to lose
groups 5-6
17. Relative atomic mass The average mass of an atom of an element/ 1/12th of the mass of
an atom of carbon-12
18. Empirical formula The simplest whole number ratio of atoms of each element present
in a compound
19. Percentage yield actual yield/theoretical yield x 100
20. Atom economy (Molecular mass of desired products/ Molecular mass of all prod-
ucts) x 100
2/8
Study online at https://quizlet.com/_71y27d
1. TOF steps 1) ionisation
2) acceleration
3) ion drift
4) detection
5) analysis
2. Electron impact Sample vaporised 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
3. 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+
4. Acceleration (TOF) positive ions accelerated using electric field so they all have the same
kinetic energy
5. Ion drift (TOF) particles with small mass have larger velocity do ions start to sepa-
rate with lightest ions reaching detector first
6. Detection (TOF) positive ions hit negatively charged plate and gain an electron which
forms a current, the larger the current the higher the abundance
7. 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
8. Electron spin Property of electron (CW or ACW)
Represented by up and down arrows
1/8
, AQA A LEVEL CHEMISTRY PAPER 1
Study online at https://quizlet.com/_71y27d
9. Orbitals Defined regions of space around nucleus where electrons most
likely to be found, each orbital holds 2 electrons
10. 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
11. Electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
12. exceptions to electron con- chromium and copper, only take one electron in 4s orbital
figuration
13. Why does ionization ener- Atoms get bigger so electrons further away from nucleus, greater
gy decrease down a group? shielding
14. Why does ionization ener- Atoms get smaller, nuclear charge increases, similar shielding
gy increase across a peri-
od?
15. Dip in ionisation energy Electrons take up higher orbital (s to p) which makes ionisation
groups 2-3 energy lower as higher orbitals have higher energy
16. Dip in ionisation energy Electron- electron repulsion in orbital makes electron easier to lose
groups 5-6
17. Relative atomic mass The average mass of an atom of an element/ 1/12th of the mass of
an atom of carbon-12
18. Empirical formula The simplest whole number ratio of atoms of each element present
in a compound
19. Percentage yield actual yield/theoretical yield x 100
20. Atom economy (Molecular mass of desired products/ Molecular mass of all prod-
ucts) x 100
2/8
