Isotopes and Mass Spec AQA

What are atoms with different mass numbers called?

• Different elements

• Same elements

• Isotopes

• Neutrons

What is the peak with the largest abundance in a mass spectrum called?

• Molecular ion peak, M+

• Base peak

• Isotopic peak

• Charge peak

Why are ions accelerated in a mass spectrometer?

• To cool them down

• To increase their mass

• To separate them based on charge

• To deflect them through the spectrometer

Which method of ionisation is used for elements with a lower molecular mass?

• Electron Impact Ionisation

• Electrospray Ionisation

• Thermal Ionisation

• Chemical Ionisation

What accelerates the ions through the mass spectrometer?

• A negatively charged plate

• A positively charged plate

• A magnetic field

• A gravitational field

What can happen to the molecular ion in the mass spectrometer?

• It can be broken down further, or fragmented

• It can be combined with other ions

• It can be dissolved in a solvent

• It can be cooled to a solid state

What is the first stage in time of flight mass spectrometry?

• Ionisation

• Acceleration

• Ion drift

• Detection

What is the result of the electron impact ionisation process?

• Formation of 1+ ions

• Formation of 2+ ions

• Formation of neutral molecules

• Formation of 3+ ions

What is the second stage in time of flight mass spectrometry?

• Acceleration

• Ionisation

• Ion drift

• Detection

What is the main advantage of using a soft ionisation technique like electrospray ionisation?

• It increases fragmentation

• It preserves the molecular structure

• It decreases ionisation efficiency

• It requires less energy