Passage
In mass spectrometry, a sample's molecules are ionized in a vacuum and then exposed to a uniform electric field created by a high-voltage plate in the acceleration chamber. The electric field accelerates the ions until they arrive at the next section of the device, designated as the separation chamber. In this section, the drifting ions are sorted by their mass-to-charge ratio (m/q) .The separation chamber in a time-of-flight mass spectrometer (TOF-MS) is linear and has no electric or magnetic fields. The ions travel at a constant velocity through the chamber until they reach the detector. The time it takes for an ion to reach the detector depends on its m/q ratio.
Figure 1 Time-of-flight mass spectrometerA magnetic sector mass spectrometer (MS-MS) has a curved separation chamber where a magnetic field is generated. The magnetic field exerts a centripetal force on drifting ions, bending their trajectories into curved paths. The radius of the curvature depends on the ion's m/q.
Figure 2 Magnetic sector mass spectrometerThe centripetal force (F) acting on a particle can be determined from its mass (m) and velocity (v) and the radius (r) of the curved path:F = mv²/rEquation 1
-What is the force felt by a doubly ionized particle in a 2,000-N/C electric field? (Note: The charge of an electron is e = 1.6 × 10⁻¹⁹ C.)

Question

Passage
In mass spectrometry, a sample's molecules are ionized in a vacuum and then exposed to a uniform electric field created by a high-voltage plate in the acceleration chamber. The electric field accelerates the ions until they arrive at the next section of the device, designated as the separation chamber. In this section, the drifting ions are sorted by their mass-to-charge ratio (m/q) .The separation chamber in a time-of-flight mass spectrometer (TOF-MS) is linear and has no electric or magnetic fields. The ions travel at a constant velocity through the chamber until they reach the detector. The time it takes for an ion to reach the detector depends on its m/q ratio.

Figure 1 Time-of-flight mass spectrometerA magnetic sector mass spectrometer (MS-MS) has a curved separation chamber where a magnetic field is generated. The magnetic field exerts a centripetal force on drifting ions, bending their trajectories into curved paths. The radius of the curvature depends on the ion's m/q.

Figure 2 Magnetic sector mass spectrometerThe centripetal force (F) acting on a particle can be determined from its mass (m) and velocity (v) and the radius (r) of the curved path:F = mv²/rEquation 1
-What is the force felt by a doubly ionized particle in a 2,000-N/C electric field? (Note: The charge of an electron is e = 1.6 × 10⁻¹⁹ C.)

Quizplus · Accepted Answer

11ecba2d_12e2_7c10_a3bf_2be8efba5d3d_MD0008_00 Charged particles are accelerated in electric fields by a force known as the electric Lorentz force. The force exerted on a particle in an electric field is equal to the product of the particle's charge (q) and the electric field strength (E): 11ecba2d_12e2_7c11_a3bf_c308ecc883fc_MD0008_00 The charge of a doubly ionized particle will be twice the charge of an electron (1.6 × 10⁻¹⁹): 11ecba2d_12e2_7c12_a3bf_cf326189059d_MD0008_00 Using the above charge as q and the given electric field strength of 2,000 N/C as E, the force exerted on the particle is: 11ecba2d_12e2_7c13_a3bf_07ad9d2789fc_MD0008_00 (Choice C) This value (3.2 × 10⁻¹⁶ N) is the force exerted on a singly ionized molecule. However, the question asks for the force exerted on a doubly ionized molecule, which has twice the charge and therefore experiences twice the force. Educational objective: The force exerted on a particle in a uniform electric field is the product of its charge and the magnitude of the electric field: F = qE.

Passage in Mass Spectrometry, a Sample's Molecules Are Ionized in a a Vacuum