Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chem 111 > Unit 2 > Flashcards

Unit 2 Flashcards

1
Q

Classical wave

A

-a disturbance that transfers energy from point to point in a medium
-Classical waves exhibit diffraction and interference, and their energy is spread out continuously in space and time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Classical mechanics

A

A set of laws describing the motion of macroscopic objects, including F=ma, the force on an object equals the mass of the object multiplied by the acceleration of the object, and F2=-F1, where F2 is the force exerted on particle 2 by particle 1 and F1 is the force exerted on particle 1 by particle 2. Also called Newtonian mechanics, after Isaac Newton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Quantum Mechanics

A

The fundamental branch of physics that describes the properties, interactions, and motions of atomic and subatomic particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

wave-particle duality

A

the concept in quantum mechanics that quantum entities exhibit particle or wave properties according to the experimental circumstances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Amplitude (A)

A

-displacement of the waveform from its undisturbed position
-the distance from center to crest or center to trough of a standing or traveling wave
-ex. you take a picture of ocean and see successive crests/troughs at various times frozen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Wavelength (λ)

A

defined as the distance of one complete wave cycle (distance between two successive crests or troughs of wave)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

crest

A

top of wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

trough

A

hollow between two wave crests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

formula for Amplitude A(x)

A

A(max)sin(2πx/λ)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

frequency (v)

A

-The number of cycles of a wave that pass a particular point per unit time
-the number of peaks/troughs observed moving past a fixed position in space per second
-ex. buoy in place such that it can float up/down but not side/side with waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Light wave-particles

A

-do not need a medium for propagation
-they can travel through a medium
-do not have mass
-transfer energy and momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

wave-particle duality of light

A

-light can either exhibit particle nature or wave nature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Light waves (electromagnetic radiation)

A

-comprise oscillating electric (E) and magnetic (H/B) fields propagating in the same direction but with amplitudes in planes that are perpendicular
-does not require a medium to propagate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

speed of light in a vacuum (c)

A

c=2.998x10^8 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

a wave’s speed of propagation

A

λ x v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

visible light wavelengths

A

light that falls in visible part of EM radiation spectrum has wavelengths between 400-700 nm

16
Q

1 nm (nanometer)

A

1 nm= 1x10^-9 m

17
Q

Rule of diffraction

A

-light diffracts when traversing through a slit with a width, d, that is on the order of the wavelength of the light
- λ/2<d<10λ

18
Q

Double-slit experiment

A

-demonstrated that when light waves traverse multiple slits and diffraction patterns from the slits overlap, constructive and destructive interference occurs due to the Superposition principle
-creates “wiggles and squiggles” that occur within a broad, overall shape dictated by diffraction of related single-slit experiment
-depends on λ of the light

19
Q

Constructive interference

A

Interaction of two waves in which their crests are aligned and their sum has greater amplitude than the original waves

20
Q

Destructive interference

A

Interaction of two waves in which the crest of one is aligned with the trough of the other and difference shows cancellation of the original waves

21
Q

Intensity of classical waves

A

about equal to A(max)^2

22
Q

Intensity

A

energy transported per unit of time over a given area

23
Q

Superposition principle

A

waves can interfere with each other constructively or destructively

24
Q

Single slit experiment

A

-the λ stays the same before and after the slit
-noticeable diffraction occurs at the slit, we observe a broad, central peak

25
Q

Photoelectric effect experiment

A

-shine light on a metal surface
-if light supplies enough energy, electrons are ejected
-these electrons generate a photocurrent (number of electrons in a given time)
-results cannot be explained through wave theory
-at constant power, the photocurrent decreases
-for different metals, the threshold frequency is different
-electrons will be ejected at the same threshold frequency no matter amount of power
-bringing in more photons causes higher number of electrons
-as frequency increases, photons bring in more energy, thus less photons enter, causing number of electrons released to decrease

26
Q

Diffraction pattern

A

Arrangement of alternating bright and dark spots produced by constructive and destructive interference of two waves

27
Q

Photon

A

a fundamental particle of light and electromagnetic radiation that has no mass and travels at the speed of light

28
Q

Energy of a photon (Eph)

A

Eph=hv=(hc)/λ

29
Q

planck’s constant

A

6.626x10^-34 m/s

30
Q

Photoelectric effect

A

the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons

31
Q

photoelectron

A

electrons which are produced when an energetic photon of radiation strikes a molecule

32
Q

Gold-Leaf electroscope experiment

A
33
Q

work function (ϕ)

A

-the “bonding energy” of a metal, the minimum amount of energy needed to remove the most loosely-held electrons from a metal
-Eph=hv0=ϕ
-if Eph is less than ϕ, no electrons are ejected at all
-when Eph is greater than ϕ, the “leftover energy” is transferred as kinetic energy (greater the Eph, greater the max KE of ejected electron)

34
Q

correspondence between photon and ejected electron

A

1:1

35
Q

Power

A

-the rate of energy transferred by the light (or EM radiation) used or generated
-Power= energy transferred/time or power x Eph = (nph x Eph)/t

36
Q

Energy transferred (I)

A

-the process where energy moves from one system to another
-I=nph x Eph

37
Q

nph

A

number of photons

38
Q

Photon rate

A

-the number of photons hitting a target per unit time
-photon rate= nph/t

Chem 111 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions