Atomic structure - Mass spec c

Question 1

What is relative atomic mass

Answer 1

Average mass of an atom of an element compared to carbon 12

Question 2

What is relative isotopic mass

Answer 2

Mass of an atom of an isotope of an element compared to an atom of carbon 12

Question 3

What is relative molecular mass

Answer 3

Average mass of a molecule compared to 1/12 an atom of carbon 12

Question 4

What are the four steps in a mass spectrometer

Answer 4

Acceleration
Ion drift
Ionisation
Detection

Question 5

What happens during a acceleration

Answer 5

+ charged ions are accelerated by elec field and have the same KE

Question 6

What happens during ion drift

Answer 6

The ions enter a region with no electric field so they drift through it and lighter ions will travel faster

Question 7

What happens during Electron spray ionisation

Answer 7

The sample is dissolved
Pushed through a nozzle at a high pressure
High voltage caused each particle to gain H+ ion
The sample is turned into a gas made from + ions

Question 8

What happens during electron impact ionisation

Answer 8

The sample is vaporised
An electron gun fires high energy electrons at it
Knocks an electron of so they become +1 ions

Question 9

What happens during detection

Answer 9

Lighter ions travel at higher speeds, heavier ions are slower . The detector detects charged particles and when the ions hit the detector it generated a current which is directly proportional to the abundance