atoms, ions and compounds Flashcards
1
Q
what are isotopes?
A
atoms of the same element with different numbers of neutrons and different masses
2
Q
what is relative isotopic mass?
A
the mass of an isotope relative to 1/12 of carbon-12
3
Q
what is relative atomic mass?
A
the weighted mean mass of an atom of the element relative to 1/12 carbon-12
4
Q
how would one use a mass spectrometer?
A
- place sample in the MS
- vaporise using heat
- bombard it with high-energy electrons (ionisation)
- accelerate the ions towards the magnetic sector
- the ions are deflected and then detected on a mass:charge ratio (m/z)
5
Q
how are the isotopes detected in a mass spectrometer?
A
- heavier ions move more slowly and are harder to deflect than lighter ions
- m/z = relative mass of ion/relative charge on ion
- each ion detected adds to its respective signal so abundances can be calculated