9. Quantum Mechanics

Electromagnetic Spectrum

What is the electromagnetic spectrum? - Invisible Labs with Craig Beals

A stellar object is emitting radiation at 3.0 mm. (a) What type
of electromagnetic spectrum is this radiation (b) If a detector
is capturing 3.0 3 108 photons per second at this wavelength,
what is the total energy of the photons detected in 1 day?

A photovoltaic cell contains a p–n junction that that converts 
solar light to electricity. An optimum semiconductor 
would have its band-gap energy matched to the wavelength 
of maximum solar intensity at the Earth’s surface. 
(a) What is the color and approximate wavelength of maximum 
solar intensity at the Earth’s surface? Refer to the 
figure for Problem 12.102.

ELECTROMAGNETIC SPECTRUM

Arrange the following kinds of electromagnetic radiation
in order of increasing wavelength: infrared, green light, red
light, radio waves, X rays, ultraviolet light.

List these types of electromagnetic radiation in order of (i)
increasing frequency and (ii) decreasing energy per photon.
a. gamma rays
b. radio waves
c. microwaves
d. visible light

Label each of the following statements as true or false. For
those that are false, correct the statement. (a) Visible light is
a form of electromagnetic radiation.

List these types of electromagnetic radiation in order of (ii) increasing energy per photon. 
a. radio waves 
b. microwaves 
c. infrared radiation 
d. ultraviolet radiation

What is Light? Maxwell and the Electromagnetic Spectrum

The Electromagnetic Spectrum

One of the emission lines of the hydrogen atom has a wavelength
of 94.974 nm. (a) In what region of the electromagnetic
spectrum is this emission found?

The ultraviolet spectrum can be divided into three regions based on wavelength: UV-A (315–400 nm), UV-B (280–315 nm), and UV-C (100–280 nm). (b) In the absence of ozone, which of these three regions, if any, are absorbed by the atmo- sphere?

Which has the higher frequency, infrared light or ultraviolet light? Which has the longer wavelength? Which has the greater energy?

Electromagnetic Radiation

(c) What type of electromagnetic radiation are these photons?

Why do the Earth and Sun have different emission spectra?

The figure shows the three lowest regions of Earth’s atmo- sphere. <img src="https://lightcat-files.s3.amazonaws.com/problem_images/afeb922879616b2a-1665501516884.jpg" alt="" /> (d) An aurora borealis is due to excitation of atoms and molecules in the atmosphere 55–95 km above Earth’s surface. Which regions in the figure are involved in an aurora borealis?

The familiar phenomenon of a rainbow results from the
diffraction of sunlight through raindrops. (a) Does the
wavelength of light increase or decrease as we proceed outward
from the innermost band of the rainbow?

What is the Electromagnetic Spectrum?

The human retina has three types of receptor cones, each 
sensitive to a different range of wavelengths of visible light, 
as shown in this figure (the colors are merely to differentiate 
the three curves from one another; they do not indicate the 
actual colors represented by each curve): 
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/2db096c0780a55ad-1664381996779.jpg" alt="" /> 
(c) Explain why the sky appears blue even though all 
wavelengths of solar light are scattered by the atmosphere.

A laser pointer used in a lecture hall emits light at 650 nm.
Using Figure 6.4, predict the color associated with this wavelength.

Stars do not all have the same temperature. The color of light
emitted by stars is characteristic of the light emitted by hot
objects. Telescopic photos of three stars are shown below:
(i) the Sun, which is classified as a yellow star, (ii) Rigel, in the
constellation Orion, which is classified as a blue-white star, and
(iii) Betelgeuse, also in Orion, which is classified as a red star.
(a) Place these three stars in order of increasing temperature.
(i) sun 
(ii) Rigel 
(iii) Betelguese

The Green Bank Telescope in West Virginia—the world’s largest steerable radio telescope—detects frequencies from 290 MHz to 90 GHz. What region or regions of the electro-magnetic spectrum are found completely or partially within its detection range?

4.37 &#215; 10&#x2212;19 s&#x2212;1

This is the energy associated with the wavelength.

6.59 &#215; 105 s&#x2212;1

The wavelength must be converted to meters.

1.51 &#215; 106 s&#x2212;1

Convert nm to m and then use the equation that relates frequency and wavelength.

6.59 &#215; 1014 s&#x2212;1

Correct, you remembered to convert nm to m.

3.01 &#215; 10&#x2212;31 s&#x2212;1

What frequency of light has a wavelength of 455 nm?

A popular kitchen appliance produces electromagnetic radiation 
with a frequency of 2450 MHz. With reference to Figure 
6.4, answer the following: (d) Which of the following 
is the appliance likely to be? (i) A toaster oven, (ii) A 
microwave oven, or (iii) An electric hotplate.

Label each of the following statements as true or false. For 
those that are false, correct the statement. (c) X rays travel faster 
than microwaves.

Which has the higher frequency, red light or violet light? Which has the longer wavelength? Which has the greater energy?

Determine which of the following statements are false and
correct them. Determine which of the following statements are false and 
correct them. (a) The frequency of radiation increases as the 
wavelength increases. (b) Electromagnetic radiation travels 
through a vacuum at a constant speed, regardless of wavelength. 
(c) Infrared light has higher frequencies than visible 
light. (d) The glow from a fireplace, the energy within a 
microwave oven, and a foghorn blast are all forms of electromagnetic 
radiation.

A diode laser emits at a wavelength of 987 nm. (a) In what 
portion of the electromagnetic spectrum is this radiation 
found? (b) All of its output energy is absorbed in a detector 
that measures a total energy of 0.52 J over a period of 32 s. 
How many photons per second are being emitted by the 
laser?

(c) What is the color of the light with <lambda> = 450 nm?

What is the ELECTROMAGNETIC SPECTRUM

A popular kitchen appliance produces electromagnetic radiation
with a frequency of 2450 MHz. With reference to Figure
6.4, answer the following: (c) If the radiation
is not visible, do photons of this radiation have more or less
energy than photons of visible light? <img src="https://lightcat-files.s3.amazonaws.com/problem_images/e7e9c8086a84b433-1664385860221.jpg" alt="" />

Visible Light (ΔE = 4.39 x 10-19 J)

Visible Light (ν = 4.11 x 1015 s-1)

Which of the following sources of electromagnetic radiation will have the highest frequency?

The wavelength at which the O2 molecule most strongly absorbs light is approximately 145 nm. (a) In which region of the electromagnetic spectrum does this light fall?

The nearest star to our sun is Proxima Centauri, at a distance of
4.3 light-years from the sun. A light-year is the distance that
light travels in one year (365 days). How far away, in km, is Proxima
Centauri from the sun?

An important reaction in the formation of photochemical smog is the photodissociation of NO : NO2 + hv → NO(g) + O(g) The maximum wavelength of light that can cause this reac- tion is 420 nm. (a) In what part of the electromagnetic spec- trum is light with this wavelength found?

Fill in the blanks with the appropriate region of electromagnetic
radiation: UV, visible, infrared.
(a) The Sun most strongly emits in the _____ and 
regions of electromagnetic radiation
(b) The atmosphere filters out biologically damaging ______
radiation from incoming solar radiation
and prevents it from reaching Earth.
(c) The Earth most strongly emits ______ radiation.
(d) Greenhouse gases absorb _______ radiation.

A photovoltaic cell contains a p–n junction that converts solar light to electricity.

(a) Silicon semiconductors with a band-gap energy of 107 kJ/mol are commonly used to make photovoltaic cells. Calculate the wavelength that corresponds to the band-gap energy in silicon.

Frequency and wavelength are inversely proportional

Energy and frequency are directly proportional.

Station 1 broadcasts with the largest amplitude.

The intensity is not specifically related to frequency.

The wave broadcast by Station 2 moves slower than that broadcast by Station 1.

 Review the equations relating energy, wavelength and frequency. 

Two radio stations broadcast at the following frequencies: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Station 1: 107.5 MHz&nbsp;&nbsp;&nbsp;	Station 2: 98.1 MHz Which of the following must be true?

It is possible to convert radiant energy into electrical energy
using photovoltaic cells. Assuming equal efficiency of conversion,
would infrared or ultraviolet radiation yield more
electrical energy on a per-photon basis?

A carbon–oxygen double bond within a sugar molecule absorbs electromagnetic radiation at a frequency of 6.0 x 1012 s-1. What portion of the electromagnetic spectrum does this represent?

(c) Which wave represents yellow light, and which represents infrared radiation?

The Hubble Space Telescope detects electromagnetic energy in the wavelength range 1.15 * 10-7 m to 2.0 * 10-6 m. What region of the electromagnetic spectrum is found completely within this range? What regions fall partially in this range?

radiation with a frequency of 6.52 x 1011 s-1

X-Ray detectors are devices that use scintillators to convert X-rays into light in order to detect X-Rays indirectly. Which of the following would be picked up by an X-Ray detector:radiation with a wavelength of 0.85 nm or a frequency of 6.52 x 1011 s-1?

Label each of the following statements as true or false. For 
those that are false, correct the statement. (b) Ultraviolet light has 
longer wavelengths than visible light.

The energy from radiation can be used to rupture chemical 
bonds. A minimum energy of 192 kJ/mol is required to 
break the bromine–bromine bond in Br2. What is the longest 
wavelength of radiation that possesses the necessary energy 
to break the bond? What type of electromagnetic radiation 
is this?

Electromagnetic Spectrum Example 1

A popular kitchen appliance produces electromagnetic radiation
with a frequency of 2450 MHz. With reference to Figure
6.4, answer the following: (b) Would the radiation produced by the
appliance be visible to the human eye? <img src="https://lightcat-files.s3.amazonaws.com/problem_images/65a2bf6582ba4c24-1664385792394.jpg" alt="" />

Wide band-gap semiconductors have a band gap between
2 and 7 electron volts (eV), where 1 eV = 96.485 kJ>mol.
The wide band-gap semiconductor GaN, used to construct
the laser in Blu-ray DVD players, has a band gap of
3.44 eV. The material in the laser, GaxIn1-x N, has some
indium substituted for gallium.
(b) If the light from the device is blue, does partial substitution
of indium for gallium increase or decrease the band
gap of GaxIn1-x N compared to GaN?

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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

Wavelength and Frequency

Wavelength&nbsp;is the distance from one crest of a wave to another, whereas frequency is the number of waves within a second.&nbsp;

Quantum Numbers: Spin Quantum Number

The Spin Quantum Number deals with the spin of an electron within an orbital.

Speed of Light

The Speed of Light in a vacuum is related to the wavelength and frequency of a light particle.

Bohr Equation

In the Bohr Equation, the energy and wavelength a photon is related to its energy shell transitions.

Quantum Numbers: Angular Momentum Quantum Number

The&nbsp;Angular Momentum Quantum Number&nbsp;gives the shape of the atomic orbitals.

Emission Spectrum

Emission Spectra is a series of lines formed when emitted light is focused by a slit and passed through a prism. &nbsp;

Introduction to Quantum Mechanics

The 4 Quantum Numbers provide us the coordinates to find the theoretical location of an electron.

Quantum Numbers: Nodes

A node is the region in an atom with zero electron density and where an electron is least likely to exist.

The Energy of Light

The Energy of Light&nbsp;involves the use of a new variable Planck's Constant.

The Electromagnetic Spectrum is the different forms of radioactive energy that exists in our universe.

Heisenberg Uncertainty Principle

Heisenberg's Uncertainty Principle&nbsp;tries to explain the potential duality of an electron behaving as either a particle or wave.&nbsp;

Quantum Numbers: Number of Electrons

The Quantum Numbers can give both the quantity and location of electrons within a given atom.&nbsp;

Quantum Numbers: Principal Quantum Number

The Principal Quantum Number gives both the size and energy of an electron shell.&nbsp;

Photoelectric Effect

What happens when light strikes the surface of a metal? The Photoelectric Effect&nbsp;can help to explain that.&nbsp;

Quantum Numbers: Magnetic Quantum Number

The Magnetic Quantum Number gives the location of an electron within a specific orbital.

Bohr Model

In the Bohr Model, electrons can move up and down to different orbitals or shells based on absorbing or releasing of energy.&nbsp;

De Broglie Wavelength

The&nbsp;De Broglie Wavelength equation relates wavelength to velocity or speed.&nbsp;