Multiple Choice
Atomic Theory: Which property is the same for all atoms of a given element?
2
views
4. Atoms and Elements
Atomic Theory
Struggling with Introduction to Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
In the context of atomic theory, what did Robert Millikan determine about the electron from his oil-drop experiment?
A
He determined the electron’s charge-to-mass ratio, , using deflection by electric and magnetic fields.
B
He measured the magnitude of the electron’s charge and showed it is quantized in integer multiples of a fundamental value.
C
He discovered the electron and demonstrated that cathode rays are streams of negatively charged particles.
D
He proposed that electrons occupy fixed circular orbits around the nucleus with quantized energies.
Verified step by step guidance1
Understand the historical context: Robert Millikan conducted the oil-drop experiment to measure a fundamental property of the electron, focusing on its electric charge.
Recall that Millikan's experiment involved balancing the gravitational force on tiny charged oil droplets with an electric force, allowing precise calculation of the droplet's charge.
Recognize that by measuring the charge on many droplets, Millikan observed that these charges were always multiples of a smallest, fundamental value, indicating quantization of electric charge.
Note that Millikan's work did not determine the charge-to-mass ratio (which was done by J.J. Thomson), nor did it involve discovering the electron or proposing electron orbits (which relate to other scientists and theories).
Conclude that Millikan's key contribution was measuring the magnitude of the electron's charge and demonstrating that electric charge is quantized in discrete units.
Related Videos
Related Practice
