2. Atoms & Elements

Millikan Oil Drop Experiment

Millikan's Oil Drop Experiment: the Charge of an Electron

Millikan determined the charge on the electron by studying
the static charges on oil drops falling in an electric
field (Figure 2.5). A student carried out this experiment using
several oil drops for her measurements and calculated the
charges on the drops. She obtained the following data:
Droplet Calculated Charge (C)
A 1.60 * 10-19
B 3.15 * 10-19
C 4.81 * 10-19
D 6.31 * 10-19
(b) What conclusion can the student
draw from these data regarding the charge of the electron?

Which of the following charges is not possible for the over-all charge on an oil droplet in Millikan’s experiment? For this problem, we’ll round the currently accepted charge of an electron to 1.602 * 10-19 C.
(a) -1.010 * 10-18 C 
(b) -8.010 * 10-19 C
(c) -2.403 * 10-18 C

An a particle, 4He2 + , has a mass of 4.00151 amu. Find the value
of its charge-to-mass ratio in C/kg.

How many electrons are necessary to produce a charge of
-1.0 C? What is the mass of this many electrons?

Elementary Charge

Millikan's oil drop experiment to determine charge of an electron - Chemistry

Charge of an Electron: Millikan's Oil Drop Experiment

On a dry day, your body can accumulate static charge from
walking across a carpet or from brushing your hair. If your body
develops a charge of -15 mC (microcoulombs), what is their collective mass?

In an alternate universe, the smallest negatively charged particle, analogous to our electron, is called a blorvek. To determine the charge on a single blorvek, an experiment like Millikan’s with charged oil droplets was carried out, and the following results were recorded :
(b) Further experiments found a droplet with a charge of 5.81 * 10-16 C. Does this new result change your answer to part (a)? If so, what is the new largest value for the blorvek’s charge?

Suppose a scientist repeats the Millikan oil-drop experiment 
but reports the charges on the drops using an unusual (and 
imaginary) unit called the warmomb (wa). The scientist obtains 
the following data for four of the drops: 
Droplet Calculated Charge (wa) 
A 3.84 * 10-8 
B 4.80 * 10-8 
C 2.88 * 10-8 
D 8.64 * 10-8 
(b) From these data, 
what is the best choice for the charge of the electron in warmombs?

STEM Experiment: Millikan Oil Drop

Suppose a scientist repeats the Millikan oil-drop experiment
but reports the charges on the drops using an unusual (and
imaginary) unit called the warmomb (wa). The scientist obtains
the following data for four of the drops:
Droplet Calculated Charge (wa)
A 3.84 * 10-8
B 4.80 * 10-8
C 2.88 * 10-8
D 8.64 * 10-8
(d) What is the
conversion factor between warmombs and coulombs?

In the Millikan oil-drop experiment (see Figure 2.5), the tiny
oil drops are observed through the viewing lens as rising,
stationary, or falling, as shown here. (a) What causes their
rate of fall to vary from their rate in the absence of an electric
field?

In an alternate universe, the smallest negatively charged particle, analogous to our electron, is called a blorvek. To determine the charge on a single blorvek, an experiment like Millikan’s with charged oil droplets was carried out, and the following results were recorded :
(a) Based on these observations, what is the largest possible value for the charge on a blorvek?

Suppose a scientist repeats the Millikan oil-drop experiment
but reports the charges on the drops using an unusual (and
imaginary) unit called the warmomb (wa). The scientist obtains
the following data for four of the drops:
Droplet Calculated Charge (wa)
A 3.84 * 10-8
B 4.80 * 10-8
C 2.88 * 10-8
D 8.64 * 10-8
(c) Based on your answer to part (b), how many
electrons are there on each of the droplets?

Imagine a unit of charge called the zorg. A chemist performs the
oil drop experiment and measures the charge of each drop in
zorgs. Based on the results shown here, what is the charge of the
electron in zorgs (z)? How many electrons are in each drop?
Drop # Charge
A -4.8 * 10 - 9 z
B -9.6 * 10 - 9 z
C -6.4 * 10 - 9 z
D -12.8 * 10 - 9 z

The Millikan Oil Drop Experiment

Millikan Oil Drop Experiment Animation

Suppose a scientist repeats the Millikan oil-drop experiment
but reports the charges on the drops using an unusual (and
imaginary) unit called the warmomb (wa). The scientist obtains
the following data for four of the drops:
Droplet Calculated Charge (wa)
A 3.84 * 10-8
B 4.80 * 10-8
C 2.88 * 10-8
D 8.64 * 10-8
(a) If all the droplets were the same size, which would fall
most slowly through the apparatus?

all the drops had a charge equal to &#8211;1.60 &#215; 10&#8211;19 C.

The charge on any oil drop was an integer multiple of the charge of an electron.

all the drops were assumed to have adsorbed the same number of electrons.

since each drop likely adsorbed a different number of electrons, the charge on each drop had to be a multiple of the electron&#8217;s charge.

Correct, during their fall the drops acquired electrons.

some of the drops contained fractions of electrons.

drops of oil were passed through a very thin film of gold atoms and their behavior was observed.

 During their fall the drops acquired electrons. 

Millikan Oil Drop Experiment Example 1

A chemist in an imaginary universe, where electrons have a different
charge than they do in our universe, performs the Millikan
oil drop experiment to measure the electron’s charge. The
charges of several drops are recorded here. What is the charge of
the electron in this imaginary universe?
Drop # Charge
A -6.9 * 10 - 19 C
B -9.2 * 10 - 19 C
C -11.5 * 10 - 19 C
D -4.6 * 10 - 19 C

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5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

13. Liquids, Solids & Intermolecular Forces

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

The Oil Drop Experiment helped with determining the fundamental charge of the electron.&nbsp;

Ions

Ions represent elements that possess either a positive charge or a negative charge.&nbsp;

Periodic Table: Charges

Elements lose or gain electrons to have the ideal number of outer shell electrons like the noble gases.&nbsp;

Law of Definite Proportions

"Different samples of a pure chemical compound always contain the same proportions of elements by mass."

Periodic Table: Classifications

The Periodic Table contains 3 Major Classifications when describing its elements

Isotopes

Isotopes are atoms of an element that have the same atomic number, but different mass number.&nbsp;

The Atom

The atom represents the basic functional unit in chemistry

Mole Concept

The Mole Concept involves the interconversions between different unit amounts of a substance.

Periodic Table: Representative Elements & Transition Metals

The Groups of the Periodic Table can be broken down into the Representative Elements and Transition Metals

Atomic Theory

John Dalton, one of the "Fathers of Chemistry"is credited with modernizing the Atomic Theory.

Subatomic Particles

The atom is composed of 3 subatomic particles:neutrons, protons, and electrons.

Periodic Table: Elemental Forms

The elements of the Periodic Table exist in different elemental forms in the natural world

Periodic Table: Phases

Under standard conditions of temperature and pressure, the elements can exist as solids, liquids or gases

Atomic Mass

The atomic mass of an element includes the masses of all 3 subatomic particles of neutrons, protons and electrons.&nbsp;

Periodic Table: Group Names

The Periodic Table can be further classified into Periods and Groups.&nbsp;

Law of Conservation of Mass

"In a chemical reaction, no matter is created or destroyed, but instead changes form."

Calculating Molar Mass

Molar Mass is a physical property that represents the mass of a substance divided by the amount of that substance.

Rutherford Gold Foil Experiment

The Gold Foil Experiment helped with the discovery of the positively charged nucleus.

Law of Multiple Proportions

“When 2 elements (A &amp; B) form different compounds, the mass of Element B that combine with 1 g of A are a ratio of whole numbers."

Periodic Table: Element Symbols

The Element Symbols of the Periodic Table represent the abbreviated form of an element