Name: electromagnetic waves: uses across the spectrum
Uploaded: 2020-09-03T13:38:27.000Z
Duration: 2 min 37 s
Channel: JoVE

K12 Standards

Pennsylvania State Academic Standards

9-12

Earth and Space Science

Earth's Systems

3.3.9-12.H

The Electromagnetic Spectrum

Het elektromagnetische spectrum is het bereik van frequenties en bijbehorende golflengten van elektromagnetische straling. Golflengte en frequentie zijn omgekeerd evenredig met elkaar;hoe langer de golflengte, hoe lager de frequentie. De energie van elektromagnetische straling is recht evenredig met de frequentie, zoals blijkt uit de vergelijking van Planck.De elektromagnetische golven met de hoogste energie hebben dus de kortste golflengten. Elektromagnetische golven worden gecategoriseerd als radiogolven, microgolven, infrarood, zichtbaar licht, ultraviolet, röntgenstralen of gammastralen, afhankelijk van hun frequenties en golflengten. Radiogolven, die worden gebruikt om signalen tussen communicatiesystemen te verzenden, hebben de langste golflengten, de laagste frequenties en de minste hoeveelheid energie.Microgolven hebben de volgende langste golflengten. Hun toepassingen variëren van radarsystemen tot het thuis verwarmen van voedsel. De volgende is infraroodstraling, die een aanzienlijk deel is van de warmtestraling die wordt uitgezonden door warme objecten.De aarde absorbeert bijvoorbeeld infraroodstraling die als onderdeel van de stralingsenergie die door de zon wordt uitgezonden, en zendt zelf infraroodstraling de ruimte in. De golflengten van zichtbaar licht zijn nog korter, variërend van 740 tot 390 nanometer. Rood licht heeft de langste golflengten en violet heeft de kortste.Menselijke ogen reageren alleen op dit smalle golflengtebereik. Ultraviolette straling heeft nog kortere golflengten. Zonlicht is de meest bekende bron van ultraviolette straling, die voldoende energie heeft om overmatige blootstelling zonnebrand te veroorzaken en huidkanker te veroorzaken.Röntgenstralen en gammastralen hebben de kortste golflengten en zijn de meest energetische vormen van elektromagnetische straling. Röntgenstralen kunnen veel stoffen passeren, maar ze gaan niet gemakkelijk door botten. Dit maakt ze een belangrijk beeldvormend instrument.Gammastralen zijn vooral bekend omdat ze vrijkomen tijdens de vervalketens van bepaalde radioactieve elementen. Hoewel er geen universeel onderscheid is tussen gamma-en röntgenstraling, wordt van gammastraling doorgaans aangenomen dat ze de kortste golflengten, hoogste frequenties en hoogste energieën hebben.

het elektromagnetische spectrum

Het elektromagnetische spectrum bestaat uit alle soorten elektromagnetische straling, gerangschikt volgens hun frequentie en golflengte. Aan elk van de verschillende kleuren zichtbaar licht zijn specifieke frequenties en golflengten verbonden, en je kunt zien dat zichtbaar licht slechts een klein deel van het elektromagnetische spectrum uitmaakt. Omdat de technologieën die zijn ontwikkeld om in verschillende delen van het elektromagnetische spectrum te werken verschillend zijn, worden om redenen van gemak en historische erfenissen doorgaans verschillende eenheden gebruikt voor verschillende delen van het spectrum. Radiogolven worden bijvoorbeeld gewoonlijk gespecificeerd als frequenties (typisch in eenheden van MHz), terwijl het zichtbare gebied gewoonlijk wordt gespecificeerd in golflengten (typisch in eenheden van nm of angstrom). <img alt="Eq1" src="https://www.jove.com/files/core/CDNSource/lessons/975/975Image_1.png" style="width: 700px;"> Figuur 1: Delen van het elektromagnetische spectrum worden weergegeven in volgorde van toenemende frequentie en afnemende golflengte. De soorten elektromagnetische golven zijn radiogolven, microgolven, ultraviolet, zichtbaar, infrarood, röntgenstraling en gammastraling. Radiogolven hebben de langste golflengten, de laagste frequenties en dragen de minste hoeveelheid energie. Ze worden gebruikt in mobiele telefoontechnologie, radio- en televisie-uitzendingen, luchtverkeersleiding, enz. Microgolven hebben kortere golflengten in vergelijking met radiogolven. Ze worden door water opgenomen en worden gebruikt om voedsel te verwarmen en te koken. Vervolgens komt infraroodstraling, die wordt uitgezonden door warme voorwerpen. De aarde absorbeert bijvoorbeeld stralingsenergie van de zon en zendt infraroodstraling uit. Een deel van de infraroodstraling wordt geabsorbeerd en opnieuw uitgezonden door de atmosfeer om de gemiddelde temperatuur van de aarde door het broeikaseffect op peil te houden. Nachtkijkers detecteren de infraroodstraling die door ons lichaam wordt uitgezonden. Zichtbaar licht is slechts een klein deel van de elektromagnetische straling, variërend van 740 tot 390 nm. Menselijke ogen kunnen alleen dit kleine golflengtebereik zien. Zichtbaar licht bestaat hoofdzakelijk uit zeven kleurcomponenten, waaronder rood, oranje, geel, groen, blauw, indigo en violet. Ultraviolette straling heeft golflengten variërend van 400 tot 10 nm. Zonlicht is de bekendste bron van UV-straling. Het bevat voldoende energie dat het bij overmatige blootstelling zonnebrand veroorzaakt. Röntgenstralen kunnen door veel stoffen heen dringen, waardoor ze een belangrijk beeldvormend hulpmiddel zijn. Tandartsen gebruiken röntgenfoto's voor diagnostische doeleinden, en luchthavenbeveiliging gebruikt ze om componenten in een koffer te visualiseren. Gammastraling heeft kleinere golflengten, hoge frequenties en hoge energieën. Gammastraling komt vrij bij kernreacties en in de natuur voorkomende radioactieve elementen. Röntgen- en gammastraling zijn de meest energetische vormen van elektromagnetische straling. Hun hoge energieën kunnen atomen en moleculen ioniseren. De ioniserende straling kan permanente verandering of schade aan biologische moleculen veroorzaken. Ze worden gebruikt om kankercellen te vernietigen. Deze tekst is aangepast van <a href="https://openstax.org/books/chemistry-2e/pages/6-1-electromagnetic-energy">Openstax, Chemistry 2e, Section 6.1: Electromagnetic Energy.</a>

Het elektromagnetische spectrum

The electromagnetic spectrum consists of all the types of electromagnetic radiation arranged according to their frequency and wavelength. Each of the ...

Education

JoVE Core

Chemistry

Scheikunde

Eén

Electronic Structure of Atoms

Elektronische structuur van atomen

KEY TERMS AND CONCEPTS

BELANGRIJKE TERMEN EN CONCEPTEN

electromagnetic waves: uses across the spectrum

The electromagnetic spectrum includes all electromagnetic radiation arranged by frequency and wavelength. Visible light is only a small part of it, and each color of visible light has its own frequency and wavelength. Different parts of the spectrum also use different units. Radio waves are usually measured in MHz, while the visible range is often measured in nm or angstroms.

The spectrum is organized from radio waves to gamma rays as frequency increases and wavelength decreases. Radio waves have the longest wavelengths, the lowest frequencies, and the least energy. They are used in cell phones, radio and television broadcasts, and air-traffic control. Microwaves have shorter wavelengths than radio waves and are absorbed by water, which is why they can heat and cook food.

Infrared radiation is next and is emitted by warm objects. The Earth absorbs energy from the Sun and gives off infrared radiation. Some of this radiation is absorbed and re-emitted by the atmosphere, which helps keep Earth’s average temperature stable through the greenhouse effect. Night vision goggles also detect the infrared radiation that our bodies emit.

Visible light spans only about 740 to 390 nm, so the human eye can see just a narrow band of electromagnetic radiation. This band includes red, orange, yellow, green, blue, indigo, and violet. Ultraviolet radiation has wavelengths from about 400 to 10 nm. Sunlight is the most familiar source of UV radiation, and too much exposure can cause sunburn.

X-rays can pass through many materials, so they are useful for imaging. Dentists use x-rays for diagnosis, and airport security uses them to view what is inside a suitcase. Gamma rays have even smaller wavelengths, higher frequencies, and higher energies. They come from nuclear reactions and naturally occurring radioactive elements. X-rays and gamma rays are the most energetic forms of electromagnetic radiation, and their ionizing radiation can damage biological molecules. Because of that, they can be used to destroy cancer cells.

Electromagnetic Waves: Uses Across the Spectrum

electromagnetic-waves-uses-across-the-spectrum

the wave nature of light

Measuring Light with Wavelength and Frequency

Light can be described as an electromagnetic wave, and its behavior helps explain many patterns seen in science. For centuries, scientists have tried to understand light. Newton used lenses and prisms to show that white light is made of the colors of the rainbow mixed together. He explained light as tiny particles moving at high speed. Other scientists, including Christiaan Huygens, showed that reflection and refraction could also be explained by treating light as a wave. At the time, people...

the electromagnetic spectrum

The electromagnetic spectrum includes all electromagnetic radiation arranged by frequency and wavelength. Visible light is only a small part of it, and each color of visible light has its own frequency and wavelength. Different parts of the spectrum also use different units. Radio waves are usually measured in MHz, while the visible range is often measured in nm or angstroms. The spectrum is organized from radio waves to gamma rays as frequency increases and wavelength decreases. Radio waves...

interference and diffraction

Wave Patterns from Light and Slits

Light can form wave patterns through interference and diffraction. When two electromagnetic waves meet with their peaks and troughs lined up, they combine into a larger wave. This is constructive interference, and the waves are in phase. When a peak of one wave meets a trough of the other, the waves reduce each other. This is destructive interference, and the result has a much lower amplitude. Diffraction is another wave behavior. When light passes through a slit that is about the same size as...

photoelectric effect

Why Light Ejects Electrons from Metals

Light can eject electrons from a metal surface when it has the right frequency. This process is called the photoelectric effect. Each metal has its own threshold frequency, which is the minimum light frequency needed to free electrons. Light below the threshold frequency cannot cause emission, even if it is very bright. When the light frequency is above the threshold, electrons are ejected. In that case, the number of electrons released is directly proportional to the intensity, or brightness,...

the bohr model

Bohr’s Quantized Atomic Orbits

Bohr’s quantized atomic orbits explain why hydrogen atoms can stay stable. Early in the twentieth century, Ernest Rutherford and his colleagues described atoms as tiny dense nuclei with lighter electrons moving around them. This picture was called the planetary model because it compared the atom to a miniature solar system, with electrons orbiting the nucleus like planets around the sun. The simplest atom is hydrogen. It has one proton in the nucleus and one electron moving around it. In the...

emission spectra

Line Spectra from Heated Gases

Line spectra are produced when heated gases give off light at specific wavelengths. In contrast, hot solids, liquids, or condensed gases radiate excess energy as a continuous spectrum. That spectrum contains an unbroken range of wavelengths. A gas at low partial pressure can produce a line spectrum when it is excited by an electric current or heated. Fluorescent light bulbs and neon signs work in this way. Each element has its own characteristic set of lines, and molecules can also produce...

the de broglie wavelength

Electron Waves and Standing Orbits

Electron waves and standing orbits explain how tiny particles can behave like waves. Large objects in the macroscopic world, like a billiard ball on a table, follow classical physics. A ball keeps moving in a straight line unless it hits another ball or a force such as friction acts on it. It also has a well-defined position, velocity, and momentum, where momentum is mass times velocity. Waves behave differently from macroscopic particles. When waves interact, they can form interference...

the uncertainty principle

Electron Position and Momentum Limits

Heisenberg’s uncertainty principle sets a limit on how precisely we can know an electron’s position and momentum at the same time. Momentum is the motion of a particle, and the two measurements affect each other. If the momentum is known more accurately, the position becomes less certain, and the reverse is also true. Heisenberg described this limit with an equation that uses Planck’s constant. The equation shows the smallest possible uncertainty for position and momentum together. It explains...

the quantum-mechanical model of an atom

Electron Orbitals in Quantum Mechanics

Quantum mechanics explains how electrons behave in atoms using waves and probability. Erwin Schrödinger built on de Broglie’s idea that an electron in hydrogen could act like a circular standing wave instead of moving in fixed circular paths. He then derived the Schrödinger equation, which became a major step in modern atomic theory. When Schrödinger applied his equation to hydrogen-like atoms, it matched Bohr’s energy expression and the Rydberg formula for hydrogen spectra. He described...

quantum numbers

Electron Orbitals and Spin

Electron orbitals are described by quantum numbers that show where an electron is most likely to be found around the nucleus. These numbers come from the quantum mechanical model, which is based on solutions of the Schrödinger equation. They also help explain why electron energy comes in set values instead of changing smoothly. The principal quantum number, n, labels the energy level. It can be 1, 2, 3, and so on, and higher n values usually mean higher electron energy. This number also tells...

atomic orbitals

Electron Regions in Atomic Orbitals

Electron regions in atomic orbitals show where an electron is most likely to be found in an atom. These three-dimensional regions are often drawn as boundary surfaces around the densest part of the cloud. The shape of an orbital depends on the angular momentum quantum number, l. This value can range from 0 to n - 1, where n is the principal quantum number. For n = 1, only l = 0 is allowed. For n = 2, both l = 0 and l = 1 are allowed. Orbitals with the same value of l form a subshell. The l =...

the pauli exclusion principle

Electron Spin and Orbital Pairing

Electron spin and orbital pairing explain why only two electrons can fit in one atomic orbital. Electron configuration describes how electrons are arranged in an atom’s orbitals. It is written with three parts: the principal quantum number, n, the orbital type, or subshell, and a superscript that shows how many electrons are in that subshell. For example, 2p4 means four electrons in a p subshell with n = 2, and 3d8 means eight electrons in a d subshell with n = 3. The three quantum numbers...

the energies of atomic orbitals

Shielding and Orbital Penetration

Shielding and orbital penetration help explain why electrons in an atom have different energies. Electrons are attracted to the positive nucleus, but they also repel one another in atoms with more than one electron. The strength of these forces depends on the charge and the distance between the particles. Opposite charges attract, like charges repel, and the force gets weaker as the particles move farther apart. An electron that stays closer to the nucleus is held more tightly. That means...

the aufbau principle and hund's rule

Electron Filling Order in Atomic Orbitals

Electron filling order in atomic orbitals follows the aufbau principle and Hund's rule. To write an electron configuration, we build atoms in order of atomic number. Starting with hydrogen and moving across the periods of the periodic table, one proton is added to the nucleus and one electron is placed into the correct subshell. This process describes the ground-state electron configurations of the elements. The aufbau principle comes from the German word aufbau, which means "to build up." It...

electron configuration of multielectron atoms

electron-configuration-of-multielectron-atoms

Valence Electrons and Noble Gas Shorthand

Valence electrons and noble gas shorthand help show how electrons are arranged in multielectron atoms. Sodium, the alkali metal with atomic number 11, has one more electron than neon. That extra electron goes into the lowest-energy subshell available, the 3s orbital, so sodium has the configuration 1s2 2s2 2p6 3s1. Electrons in the outermost shell, where n is highest, are called valence electrons. Electrons in the inner shells are called core electrons. Because core electrons often match a...

key terms and concepts

Explore the electromagnetic spectrum from radio waves to gamma rays, including visible light, infrared, UV, X-rays, and their real-world uses.

Electromagnetic Waves: Uses Across the Spectrum | JoVE K12

chemistry

JoVE Core Chemistry brings general chemistry concepts to life using concise and easy-to-understand animated video lessons. Plus, in the scientist-in-action videos, we demonstrate classical and original research experiments performed in today's laboratories worldwide.

Weather and Climate

3.3.9-12.E

Physical Science

Waves and Electromagnetic Radiation

3.2.9-12.X

Louisiana Student Standards for Science

High School

Earth Science

Earth’s Systems

HS-ESS2-4

Tennessee Academic Standards

Physics

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Waves and Their Applications in Technologies for Information Transfer

PHYS.PS4.7

PHYS.PS4.8

Arizona Science Standards

HS+C.P1

HS+C.P1U1.2

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New Jersey Student Learning Standards for Science

HS-PS4-4

Alabama Course of Study Science

Matter and Its Interactions

9-12.C.1.1.c

Earth's Place in the Universe

9-12.ESS.1.2

9-12.ESS.1.2.a

Next Generation Science Standards

Florida Department of Education

SC.912.E.5

SC.912.E.5.8

SC.912.P.8

SC.912.P.8.3

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SC.912.P.10.19

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South Carolina College and Career Ready Science Standards

C-PS4-4

C-PS4-5

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New York State Science Learning Standards

HS. Chemical Reactions

HS-PS1-7.

HS. Waves and Electromagnetic Radiation

HS-PS4-3.

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3.3.9-12.I

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3.3.9-12.K

Electromagnetic Waves: Uses Across the Spectrum

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