Electromagnetic (EM) radiation is a type of energy that is all around us and takes countless forms, such as radio waves, microwaves, X-rays and gamma rays. Sunshine is likewise a kind of EM energy, however visible light is only a small portion of the EM spectrum, which includes a broad variety of electromagnetic wavelengths.

You are watching: Arrange the following in order of decreasing wavelength

Electromagnetic theory

Electricity and also magnetism were as soon as thought to be different forces. However, in 1873, Scottish physicist James salesman Maxwell arisen a unified theory of electromagnetism. The examine of electromagnetism encounters how electrically charged particles communicate with every other and with magnetic fields.

There are 4 main electromagnetic interactions:

The pressure of attraction or repulsion between electric charges is inversely proportional come the square that the distance in between them.Magnetic poles come in pairs the attract and also repel every other, much as electric charges do.An electric existing in a wire produces a magnetic field whose direction relies on the direction the the current.A moving electrical field to produce a magnetic field, and also vice versa.

Maxwell also developed a collection of formulas, called Maxwell"s equations, to explain these phenomena.

Waves and fields

EM radiation is developed when an atom particle, such together an electron, is increased by an electric field, bring about it to move. The motion produces oscillating electric and magnetic fields, which travel at ideal angles come each various other in a bundle of light energy called a photon. Photons travel in harmonic tide at the more quickly speed feasible in the universe: 186,282 miles per second (299,792,458 meters every second) in a vacuum, also known as the rate of light. The tide have particular characteristics, provided as frequency, wavelength or energy.

Electromagnetic tide are created when an electrical field (shown in red arrows) couples with a magnetic field (shown in blue arrows). Magnetic and electric areas of one electromagnetic wave space perpendicular to each other and to the direction of the wave. (Image credit: NOAA.)

A wavelength is the distance in between two continually peaks of a wave. This distance is given in meters (m) or fractions thereof. Frequency is the variety of waves that type in a given length of time. That is typically measured together the number of wave cycles per second, or hertz (Hz). A short wavelength means that the frequency will certainly be higher because one cycle have the right to pass in a shorter amount that time, follow to theUniversity that Wisconsin. Similarly, a longer wavelength has actually a lower frequency because each bike takes longer to complete.

The EM spectrum

EM radiation spans one enormous selection of wavelengths and frequencies. This variety is recognized as the electromagnetic spectrum. The EM spectrum is generally divided into 7 regions, in bespeak of diminish wavelength and also increasing energy and also frequency. The usual designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and also gamma rays. Typically, lower-energy radiation, such together radio waves, is expressed as frequency; microwaves, infrared, visible and UV light space usually expressed as wavelength; and higher-energy radiation, such together X-rays and gamma rays, is express in terms of power per photon.

The electromagnetic spectrum is generally separated into 7 regions, in stimulate of to decrease wavelength and also increasing energy and frequency: radio waves, microwaves, infrared, clearly shows light, ultraviolet, X-rays and also gamma rays. (Image credit: Biro Emoke Shutterstock)

Radio waves

Radio waves space at the lowest selection of the EM spectrum, v frequencies of up to about 30 billion hertz, or 30 gigahertz (GHz), and also wavelengths greater than around 10 millimeter (0.4 inches). Radio is used generally for interactions including voice, data and entertainment media.


Microwaves loss in the selection of the EM spectrum between radio and also IR. They have actually frequencies from about 3 GHz up to around 30 sunshine hertz, or 30 terahertz (THz), and wavelengths of about 10 mm (0.4 inches) come 100 micrometers (μm), or 0.004 inches. Microwaves are used for high-bandwidth communications, radar and as a heat source for microwave ovens and also industrial applications.


Infrared is in the range of the EM spectrum between microwaves and visible light. IR has frequencies from around 30 THz up to around 400 THz and also wavelengths of around 100 μm (0.004 inches) come 740 nanometers (nm), or 0.00003 inches. IR irradiate is invisible to human eyes, yet we have the right to feel it as heat if the soot is sufficient.

clearly shows light

Visible light is found in the center of the EM spectrum, between IR and also UV. It has frequencies of about 400 THz to 800 THz and also wavelengths of about 740 nm (0.00003 inches) come 380 nm (.000015 inches). Much more generally, visible light is characterized as the wavelength that are visible to most person eyes.


Ultraviolet irradiate is in the selection of the EM spectrum in between visible light and also X-rays. It has actually frequencies of about 8 × 1014to 3 × 1016Hz and wavelengths of about 380 nm (.000015 inches) to around 10 nm (0.0000004 inches). UV light is a component of sunlight; however, that is invisible to the person eye. The has many medical and also industrial applications, but it can damage living tissue.


X-rays are approximately classified into two types: soft X-rays and hard X-rays. Soft X-rays consist of the variety of the EM spectrum between UV and gamma rays. Soft X-rays have actually frequencies of about 3 × 1016to around 1018Hz and wavelengths of about 10 nm (4 × 10−7inches) to about 100 picometers (pm), or 4 × 10−8inches. Difficult X-rays occupy the same region of the EM spectrum together gamma rays. The only difference between them is your source: X-rays are created by speeding up electrons, when gamma light ray are produced by atom nuclei.

See more: Which Of The Enzymes Covalently Connects Segments Of Dna? Dna Replication


Gamma-rays are in the selection of the spectrum above soft X-rays. Gamma-rays have actually frequencies better than around 1018Hz and wavelengths of much less than 100 pm (4 × 10−9inches). Gamma radiation reasons damage to life tissue, which makes it beneficial for killing cancer cells when used in closely measured sheep to little regions. Uncontrolled exposure, though, is exceptionally dangerous come humans.