Name: em spectrum, waves, and photon energy
Uploaded: 2024-12-05T18:32:03.000Z
Duration: 1 min 10 s
Channel: JoVE

K12 Standards

Pennsylvania State Academic Standards

9-12

Physical Science

Waves and Electromagnetic Radiation

3.2.9-12.X

dual-nature-of-electromagnetic-em-radiation

Dual Nature of Electromagnetic (EM) Radiation

Electromagnetic radiation can be considered as an electromagnetic wave propagating through space and as energy-containing particles called photons.
Electromagnetic radiation is characterized by its frequency, which is the number of repeating waves that pass a given point in a fixed time. At the same time, it interacts with matter and transfers a set amount of energy, like a particle.
The energy of a photon is proportional to the frequency of the radiation, expressed by the Planck equation. The set of radiation with all possible frequencies is known as the electromagnetic spectrum.
The electromagnetic spectrum can also be divided into wavelength ranges, which are the distances between consecutive peaks or troughs in the wave.
Wavelength and frequency are related to the velocity of the radiation through a medium, which is approximated as the speed of light in a vacuum.
The frequency and wavelength are inversely related to each other, so the higher the frequency, the lower the wavelength.

dual nature of electromagnetic (em) radiation

Electromagnetic (EM) radiation consists of electric and magnetic field components oscillating in planes perpendicular to each other and mutually perpendicular to radiation propagation through space. EM radiation can be classified as a wave, characterized by the properties of waves such as wavelength (denoted as &#955;) and frequency (represented by &#957;).
Wavelength is the distance between two consecutive peaks (the highest point) or troughs (the lowest point) in the wave. Frequency is the number of repeating waves or wave cycles that pass a given point in a fixed time. Different types of electromagnetic radiation have varying wavelengths and frequencies. The electromagnetic spectrum is the ordered collection of electromagnetic radiation grouped by frequency or wavelength. The wavelength and frequency are related to the speed of the radiation through a medium. The speed of radiation in a vacuum (denoted as c) is a universal physical constant with a value of approximately 3 &#215; 108 m/s.
<img alt="Speed of light equation, c=&#955;&#957;=3&#215;10&#8312; m/s, formula, physics, wave frequency, wavelength." src="/files/ftp_upload/13022/13022_PT_Figure_1.svg" style="text-align: center; height: 17px;" data-altupdatedat="1761830439000" data-alt="Figure1" />
Therefore, wavelength and frequency are inversely related. Radiation with a high frequency features a low wavelength, and vice versa.
<img alt="Equation diagram representing static equilibrium; &#931;Fx=0 condition illustrated." src="/files/ftp_upload/13022/13022_PT_Figure_2.svg" style="text-align: center; height: 40px;" data-altupdatedat="1761830439000" data-alt="Figure2" />
In addition to behaving like a wave, electromagnetic radiation can also be considered a collection of particles called photons. A photon is the smallest unit or "quantum" of light or electromagnetic radiation. It has no mass or charge but carries energy. Each photon possesses a definite quantity of energy, which can be transferred to matter upon interaction. The energy of a photon (denoted as E) is directly proportional to the frequency and inversely proportional to the wavelength. The equation relating a photon's energy to its radiation frequency is known as Planck&#8217;s equation.
<img alt="Quantum energy equation, E=hv=hc/&#955;, formula for photon energy, physics and photonics studies." src="/files/ftp_upload/13022/13022_PT_Figure_3.svg" style="text-align: center; height: 34px;" data-altupdatedat="1761830439000" data-alt="Figure3" />
Planck&#8217;s constant is denoted by h with a value of 6.626 &#215; 10&#8722;34 m2&#8201;kg&#8201;s&#8722;1.

Electromagnetic (EM) radiation consists of electric and magnetic field components oscillating in planes perpendicular to each other and mutually ...

Education

JoVE Core

Analytical Chemistry

Unit 1

Introduction to Molecular Spectroscopy

KEY TERMS AND CONCEPTS

em spectrum, waves, and photon energy

Electromagnetic radiation has both wave and particle features. It includes electric and magnetic field components that oscillate in planes perpendicular to each other. These fields are also perpendicular to the direction the radiation moves through space.

As a wave, electromagnetic radiation is described by wavelength and frequency. Wavelength is the distance between two consecutive peaks or troughs. Frequency is the number of wave cycles that pass a point in a fixed time. The electromagnetic spectrum is the ordered group of electromagnetic radiation based on wavelength or frequency.

Wavelength and frequency are linked to the speed of radiation in a medium. In a vacuum, the speed of radiation is a universal constant, c, and it is about 3 × 10^8 m/s. Because of this, wavelength and frequency are inversely related. High-frequency radiation has a low wavelength, and low-frequency radiation has a higher wavelength.

Electromagnetic radiation can also be described as particles called photons. A photon is the smallest unit, or quantum, of light or electromagnetic radiation. It has no mass or charge, but it carries energy. Each photon has a definite amount of energy that can be transferred to matter when it interacts with it.

Photon energy depends on frequency and wavelength. Energy is directly proportional to frequency and inversely proportional to wavelength. This relationship is given by Planck’s equation. In this equation, Planck’s constant is h, and its value is 6.626 × 10−34 m2 kg s−1.

EM Spectrum, Waves, and Photon Energy

Electromagnetic radiation has both wave and particle features. It includes electric and magnetic field components that oscillate in planes perpendicular to each other. These fields are also perpendicular to the direction the radiation moves through space. As a wave, electromagnetic radiation is described by wavelength and frequency. Wavelength is the distance between two consecutive peaks or troughs. Frequency is the number of wave cycles that pass a point in a fixed time. The electromagnetic...

interaction of em radiation with matter: spectroscopy

interaction-of-em-radiation-with-matter-spectroscopy

EM Radiation and Matter in Spectroscopy

Electromagnetic radiation and matter interact in ways that reveal details about atoms and molecules. In spectroscopy, scientists study how EM radiation is absorbed, emitted, transmitted, reflected, or scattered by a substance. This helps identify its chemical composition and properties. EM radiation behaves as both a wave and a particle. As a wave, it has intensity and amplitude. Intensity, also called irradiance, is the number of photons that strike a given area in a certain time. Amplitude...

molecular spectroscopy: absorption and emission

molecular-spectroscopy-absorption-and-emission

Molecular Energy Levels in Spectroscopy

Molecular spectroscopy describes how molecules absorb and emit light by moving between energy levels. These levels are called quantum states. Unlike atoms, molecules also have rotational and vibrational energy levels, so their energy structure is more complex. Each level is separated by an energy gap. The gaps between electronic, vibrational, and rotational levels are very different in size. A diatomic molecule can be used to show these three kinds of energy levels. A molecule can absorb a...

spectrophotometry: introduction

Spectrophotometry for Absorption Spectra

Spectrophotometry measures how a material absorbs, reflects, diffracts, or transmits electromagnetic radiation. It compares the intensity of radiation before and after it interacts with the material. The result shows how the material responds to different wavelengths. A spectrophotometer is the device used for this measurement. It includes a source of electromagnetic radiation, a slot for the sample, and a detector. The detector measures the radiation that leaves the material, including...

ultraviolet and visible (uv&ndash;vis) spectroscopy: overview

ultraviolet-and-visible-uvvis-spectroscopy-overview

UV-Vis Spectroscopy for Light Absorption

UV-Vis spectroscopy measures how materials absorb ultraviolet and visible light. It is a useful analytical method because it is versatile, simple to use, and gives results quickly. Scientists use it for both qualitative and quantitative analysis. When UV-Vis radiation passes through a sample, molecules absorb specific wavelengths based on the energy needed for electronic transitions. This absorption moves atoms or molecules from a ground state to an excited state. If a molecule absorbs UV...

uv&ndash;vis spectroscopy: molecular electronic transitions

uvvis-spectroscopy-molecular-electronic-transitions

UV-Vis Spectroscopy and Molecular Absorption

UV-Vis spectroscopy shows how molecules absorb ultraviolet and visible light. It is used to study electronic structure by tracking how electrons move between molecular orbitals. The absorbed light must match the energy gap between the ground state and an excited state. In this process, an electron moves from the highest occupied molecular orbital, or HOMO, to the lowest unoccupied molecular orbital, or LUMO. This jump raises the electron to a higher energy level. The energy difference between...

uv&ndash;vis spectrometers

UV-Vis Spectrophotometer Parts and Samples

A UV-visible spectrophotometer measures how much UV and visible light a sample absorbs. It uses a light source, a wavelength selector, a sample holder, and a detector to build the spectrum. This makes it useful for checking liquid samples in the lab. The light source depends on the region being measured. A deuterium lamp provides UV radiation, and a tungsten lamp provides visible radiation. A monochromator or prism acts as a diffraction grating and splits the incoming light into different...

uv&ndash;vis spectrum

How Molecular Structure Shapes UV-Vis Bands

UV-Vis spectroscopy shows how a molecule absorbs light in the ultraviolet and visible ranges. When light passes through a substance, some of it is absorbed and the rest is reflected or transmitted. Molecules that absorb between 180 and 400 nm give a UV spectrum, while absorption in the 400 to 780 nm range gives a visible spectrum. A UV-Vis spectrum is a plot of absorbance versus wavelength. The y-axis shows molar absorptivity, ε, or log ε, and the x-axis shows wavelength. Absorbance describes...

uv&ndash;vis spectroscopy: beer&ndash;lambert law

Using Absorbance to Find Concentration

The Beer-Lambert law links absorbance, concentration, and path length in a solution. It is based on ideas from Johann Heinrich Lambert and August Beer. Their work helps explain how light changes as it passes through a medium. Lambert's law says that when light passes through a medium, the loss in intensity is directly proportional to the original intensity and the path length. Beer’s law adds that the transmittance of a solution stays constant if the product of concentration and path length...

photoluminescence: fluorescence and phosphorescence

photoluminescence-fluorescence-and-phosphorescence

Light Emission from Excited Molecules

Photoluminescence is light emission from molecules after they absorb light energy. A substance takes in photons, which raises electrons to excited energy levels. The electrons then relax back to the ground state and release light. This process appears in many materials, including semiconductors, organic compounds, and inorganic compounds. The main role of electron spin helps separate photoluminescence into fluorescence and phosphorescence. In a singlet spin state, two electrons share the same...

variables affecting phosphorescence and fluorescence

variables-affecting-phosphorescence-and-fluorescence

Factors That Change Light Emission in Molecules

Fluorescence and phosphorescence depend on several factors that change how molecules emit light. These effects matter in analytical chemistry, biological imaging, and materials science because they help scientists detect molecular properties and see cellular structures. Molecular structure is one of the main influences. Aromatic compounds with low-energy pi-bonding to pi-non-bonding transitions often give strong fluorescence. Aliphatic and alicyclic carbonyl compounds, as well as highly...

deactivation processes: jablonski diagram

Jablonski Diagram: Light Loss Pathways

Jablonski diagrams show how excited molecules lose energy after absorbing light. They are used to track both light-emitting and non-light-emitting steps in luminescence. The diagram gives a simple picture of the energy states a molecule can move through. The lowest line in a Jablonski diagram is the ground-state energy of the molecule. This state is usually a singlet state, and it represents the condition of most molecules in solution at room temperature. The lines above it show vibrational...

photoluminescence: applications

Fluorescent and Phosphorescent Analysis

Photoluminescence is useful in chemical analysis because it is sensitive and selective. It can support both direct and indirect measurements of an analyte, which is the substance being tested. When an analyte has a strong quantum yield, it can be measured directly by fluorescence or phosphorescence. Indirect analysis is used when the analyte is not naturally fluorescent or phosphorescent, or when its quantum yield is poor. One approach is to react the analyte with a reagent to make a...

fluorescence and phosphorescence: instrumentation

fluorescence-and-phosphorescence-instrumentation

Measuring Fluorescence and Phosphorescence

Fluorometers and spectrofluorometers are instruments used to measure molecular fluorescence. They do this by choosing specific excitation and emission wavelengths. The two instruments use different light sources and wavelength-selection methods. A fluorometer uses absorption interference filters to select the excitation and emission wavelengths. Its excitation source is usually a low-pressure mercury vapor lamp. This lamp gives intense lines across the ultraviolet and visible regions.

key terms and concepts

Learn how electromagnetic radiation is described by wavelength, frequency, and photons, and how Planck’s equation links photon energy to frequency.

EM Spectrum, Waves, and Photon Energy | JoVE K12

analytical chemistry

JoVE Core Analytical Chemistry simplifies complex chemical principles by breaking them down into clear, engaging animations, making topics from SI Units to NMR spectroscopy more accessible and straightforward. Additionally, the scientist-in-action videos highlight the application of these concepts in real-world research conducted in laboratories globally.

Louisiana Student Standards for Science

High School

Earth Science

Earth’s Systems

HS-ESS2-1

HS-ESS2-4

Chemistry

Energy

HS-PS3-3

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Physics

Waves

Light phenomena

Tennessee Academic Standards

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Waves and Their Applications in Technologies for Information Transfer

PHYS.PS4.6

PHYS.PS4.7

CHEM1.PS4.1

Virginia  Standards of Learning

HIgh School

PH.9

PH.9.a

Minnesota Academic Standards in Science

3.2.2 9P.3.1.1.2

Arizona Science Standards

HS+C.P1

HS+C.P1U1.2

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

HS-PS4-3

HS-PS4-4

Alabama Course of Study Science

Earth and Space Science

Earth's Place in the Universe

9-12.ESS.1.2

9-12.ESS.1.2.a

9-12.ESS.1.2.b

Florida Department of Education

SC.912.E.5

SC.912.E.5.8

SC.912.P.10

SC.912.P.10.19

Texas Essential Knowledge and Skills

PHYS.8

PHYS.8.E

PHYS.8.F

PHYS.9

PHYS.9.A

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

C-PS4-4

C-PS4-5

P-PS4-1

P-PS4-4

Travelling Waves

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Velocity and Acceleration of a Wave

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Energy and Power of a Wave

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3.2.9-12.T

Interference and Superposition of Waves

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Sound Waves: Interference

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Two ...

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The Electromagnetic Spectrum

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Electromagnetic Wave Equation

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propagation-speed-of-electromagnetic-waves

Propagation Speed of Electromagnetic Waves

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Consider a plane ...

Electromagnetic Waves in Matter

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Energy Carried By Electromagnetic Waves

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Intensity Of Electromagnetic Waves

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Momentum And Radiation Pressure

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Radiation Pressure: Problem Solving

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3.2.9-12.V

Absorption of Radiation

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3.2.9-12.W

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Molecular Spectroscopy: Absorption and Emission

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EM Spectrum, Waves, and Photon Energy

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