Atomic Structure: Mass Spectrometer

Question 1

Do all of the isotopes of an element react the same?

Answer 1

YES.

Question 2

What is the abudance of an isotope?

Answer 2

= how common it is

Question 2

How to determine the mass number and abudance of isotopes?

Answer 2

= use a mass spectrometer

Question 3

What are the stages of the time of flight mass spectrometer?

Answer 3

1- take a sample of the element + place in sample chamber (SAMPLE CONTAINS different isotopes of that element).
2- Atoms go through ionisation, converts all atoms into positive ions
3- positive ions are now attracted to a negativley charged plate, negative charge causes ions to accelerate- increases kinetic energy of ions

4- once the ions pass through the negative plate they stop accelerating and drift down the chamber towards the detector

5- at the end of the drift chamber ions reach the detector each positive ion gains electrons from the detector - transfer of electrons causes current flow

Question 4

All of the ions with the same charge will have the same what?

Answer 4

= same kinetic energy

Question 5

How do the ions drift down the chamber?

Answer 5

= ions drift down the chamber at different velocities
= lighter ions moving faster than heavier ions

Question 6

How does the machine determine the mass of the isotope?

Answer 6

= time taken to move down the drift chamber

Question 7

How does the machine determine the abundance of each isotope?

Answer 7

= size of the current produced when each isotope hits the detector

Question 8

What is the interior of the mass spectrometer like?

Answer 8

= vacuum
= prevents ions from colliding with molecules in air

Question 9

What is the m/z ratio?

Answer 9

= ratio of the mass of each ion
= to it’s charge