Atoms, Ions and Compounds (2) Flashcards
proton charge
positive
electron charge
negative
cation
positive ion - lost electrons
anion
negative ion - gained electrons
mass spectrometer
used to find % abundance of isotopes in a compound
m/z ratio
relative mass of an ion/ relative charge of an ion
relative atomic mass from % and m/z
(% multiplied by m/z ) divided by 100
relative atomic mass from unrounded atomic mass and m/z
( unrounded number multiplied by m/z ) divided by m/z values added.
hydroxide
OH -
nitrate
NO3 -
carbonate
CO3 2-
sulphate
SO4 2-
phosphate
PO4 3-
ammonium
NH4 +
how a mass spectrometer works - step 1
Vapourisation - sample is injected and vapourised into gas
how a mass spectrometer works - step 2
Ionisation - The spectrometer has an electron gun that has a potential difference between 2 plates and electrons move from the cathode to the anode. As gas moves past the gun, some of these electrons knock an electron of it’s outer shell. This means it’s ionised.
how a mass spectrometer works - step 3
Electrostatic acceleration - The positive ions are accelerated towards a negative plate and this helps focus fragments as beam
how a mass spectrometer works - step 4
Magnetic deflection - the different mass and charge of the fragments are now sorted by a magnetic field. Those with a greater mass will be deflected less, those with a greater charge will be deflected more
how a mass spectrometer works - step 5
Detection - The fragments are now detected and accept electrons, one positive charge will accept one electron. This will set up a current as the detector is giving electrons
