Atomic theory 2

Question 1

Define (i) mass number, (ii) relative atomic mass of an element.

Answer 1

(i) The mass number is the number of protons plus neutrons in the nucleus of an atom.
(ii) The average mass of an atom of an element compared to 1/12 the carbon-12 isotope, taking relative abundances of isotopes into account.

Question 2

A sample of magnesium metal was introduced into a mass spectrometer and vaporised. What were the next three fundamental processes that occurred in the mass spectrometer?

Answer 2

• Ionisation
• Acceleration
• Seperation

Question 3

Define (i) mass number, (ii) relative atomic mass.

Answer 3

(i) The mass number is the number of protons plus neutrons in the nucleus of an atom.
(ii) The average mass of an atom of an element compared to 1/12 the carbon-12 isotope, taking relative abundances of isotopes into account.

Question 4

Three of the five fundamental processes that occur in mass spectrometry are detection, acceleration and vaporisation of substance. What are the two other fundamental processes that occur in mass spectrometry?

Answer 4

• Ionisation

- Separation

Question 5

List all five processes of the mass spectrometry in the order that they occur.

Answer 5

• Vaporisation
• Ionisation
• Acceleration
• Separation
• Detection

Question 6

What is the principle on which the mass spectrometer is based?

Answer 6

The principle involved is that different ions are separated according to their masses when moving in a magnetic field.