Mass spectrometry and relative atomic mass Quiz
Studying this course? Keep your progress in one place.
Pick an answer for each. Quizzes never use energy.
5 questions, one answer each
Each answer is checked as you go, with why.
See all 5 questions
1. A sample of boron contains ¹⁰B (19.9%) and ¹¹B (80.1%). What is its relative atomic mass to 3 significant figures?
- A. 10.5
- B. 10.8
- C. 11.0
- D. 10.2
2. ²⁴Mg⁺ and ²⁶Mg⁺ ions are accelerated to the same kinetic energy. Which reaches the detector first?
- A. ²⁴Mg⁺, because it is lighter and faster
- B. ²⁶Mg⁺, because it is heavier and faster
- C. They arrive together
- D. ²⁶Mg⁺, because it has a greater charge
3. Why are all ions given the same kinetic energy in a TOF mass spectrometer?
- A. To make all ions have the same charge
- B. To make the ions stable
- C. To increase the abundance of the ions
- D. So that the time of flight depends only on mass
4. What does the size of the current at the detector show?
- A. The mass of the ions
- B. The speed of the ions
- C. The relative abundance of the ions
- D. The number of protons in the ions
5. A molecule gives a molecular ion peak at m/z 78 using electron impact. What is the relative molecular mass?
- A. 77
- B. 78
- C. 79
- D. 156