Electromagnetic Spectrum - Online Tutor, Practice Problems & Exam Prep

The electromagnetic spectrum encompasses a range of electromagnetic radiation, from long radio waves to gamma rays, characterized by varying wavelengths and frequencies. As one moves from radio waves to gamma rays, the wavelength decreases (from 10⁸ to 10^-16 meters) while the frequency increases (from 100 to 1024 hertz). The visible light spectrum, a segment of the electromagnetic spectrum observable without instruments, ranges from 700 nanometers (red light) to 380 nanometers (violet light). To recall the order of the spectrum, one can use the mnemonic "Large Root Martians Invented Very Unusual X-ray Guns," representing long radio waves, radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays, respectively. Additionally, the visible light spectrum is flanked by infrared on the red end and ultraviolet on the violet end.

Electromagnetic Spectrum

Now we have the electromagnetic spectrum. We're going to see the electromagnetic spectrum is a continuum of electromagnetic radiation containing all wavelengths and all frequencies. Now we're going to say here, if we take a look at the electromagnetic spectrum, we're going to set it up where we have our long radio waves here on the far left and we're going to proceed towards the right until we get to gamma rays.

Realize here that we have on the top our frequency, which is in Hertz and Justice. Observe what's happening to the frequency. It goes from 100 all the way to 1024 on the bottom. We also have our wavelength, which is in meters. Observe what's happening with it. We have 10-8. And as we go towards the right what's happening, it goes 10-16.

Now the electromagnetic spectrum, these are all the ones that you need to remember. So we have our long radio waves. Then we have our regular radio waves, which have AM and FM. So if you look in your car, if you're playing AM stations, you'll realize that the frequency is a lot smaller. If you flip over to the FM radio stations, they're a lot higher in terms of their frequency values. Then we have microwave infrared.

This portion here where we see colors is the visible light spectrum, the part that we can see without any instrumentation. Then we have ultraviolet, X-ray, and then gamma rays. Of course there's cosmic rays, but don't worry about that. Now observing what we saw with frequency and wavelength going from left to right, we would see as we move from radio waves to gamma rays, the wavelength we see it decreases because we went from 108 to 10-16. And then we see the frequency increased where we went from 100 to 1024.

So gamma rays would have the highest frequency but lowest wavelength, and long radio waves would have the longest wavelength but longest wavelength here. Sorry, longest wavelength here, but the smallest frequency. Now I know that's a lot of terms to memorize, so let's use our memory tool here. Just remember the order is large. Rude Martians invented very unusual X-ray guns, so large is for long radio waves. Rude is for radio waves, Martians is for microwave. Invented is for infrared visible light spectrum is very unusual is for UV or ultraviolet, X-ray is for X-ray and then guns here stands for gamma rays.

So just remember these these terms represent our entire electromagnetic spectrum in which you're responsible in knowing right and use this memory tool to help you remember the order that they're found in. Now that we've seen this electromagnetic spectrum, move on to our next video and let's take a look at an example question.

Electromagnetic Spectrum Example 1

So here we're going to use our memory tool to help us with this example question. It says which kind of electromagnetic radiation contains the greatest amount of energy per atom. Here, remember, as we move from left to right, we're going to say that our frequency increases, so μ is increasing. And this is important to know because remember, energy and frequency are directly related, so the greatest amount of energy would correlate to the highest frequency.

So who's most to the right here? If we look, microwave is for Martians, so that's out. X-ray is over here. And the only thing higher than that is gamma rays. And we don't have gamma rays listed as an option. So here our answer would have to be choice B.

Remember, large rude Martians invented very unusual X-ray guns. Stands for long radio waves, radio waves. Here we have microwaves. Here we have infrared, the visual light spectrum. We have UV light, X-ray and then gamma ray.

Electromagnetic Spectrum

So, the visible light spectrum represents a small portion of the continuum, the electromagnetic spectrum itself, that can be seen without the aid of instruments by us. And here we're going to say that in order to remember the colors involved with the visible light spectrum, just remember Roy G Biv. Here R is red. Then we have orange, yellow we have here green, blue, indigo, and Violet.

Now realize that sometimes in more modern visible light spectrums, they'll combine indigo and Violet together. And just say it's Violet. And when we're talking about the visible light spectrum, realize that it ranges from 700 nm for red light all the way to around 380 nm for Violet light. And remember, in terms of the electromagnetic spectrum, we're going to say that red is near infrared and then the Violet end is next to ultraviolet.

Now that's blue, but you get what I mean. So that's a good way of remembering what other electromagnetic radiations are near the visible light spectrum. Red is next to the infrared and then Violet is next to ultraviolet. So just remember, the visible light spectrum is important to us because that's what we can see with our bare eyes without the use of any types of instruments.

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

• A. Visible Light (λ = 595 nm)
• B. Visible Light (ΔE = 4.39 x 10^-19 J)
• C. Visible Light (λ = 690 nm)
• D. Visible Light (ν = 4.11 x 10¹⁵ s^-1)

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?

• A. Radio Waves
• B. Micowave
• C. Infrared
• D. Green Light
• E. Gamma Ray

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?

• A. radiation with a wavelength of 0.85 nm
• B. radiation with a frequency of 6.52 x 10¹¹ s^-1

Here’s what students ask on this topic:

What is the electromagnetic spectrum?

The electromagnetic spectrum is a continuum that showcases all the different types of electromagnetic radiation, ranging from very short wavelengths (like gamma rays) to very long wavelengths (like radio waves). These waves all travel at the speed of light but differ in their wavelength and frequency. The spectrum is typically divided into seven regions, in order of decreasing frequency and increasing wavelength: gamma rays, X-rays, ultraviolet light, visible light, infrared radiation, microwaves, and radio waves.

Visible light, which is the part of the spectrum detectable by the human eye, is only a small portion of the entire spectrum. Each type of electromagnetic radiation has unique properties and interacts with matter differently, which makes them useful for a variety of applications, from medical imaging (using X-rays) to communication (using radio waves). Understanding the electromagnetic spectrum is crucial in fields like physics, astronomy, and various engineering disciplines, as it underpins a lot of modern technology and scientific research.

How are different types of radiation arranged along the electromagnetic spectrum?

Different types of radiation are arranged along the electromagnetic spectrum based on their wavelength and frequency. The electromagnetic spectrum is a continuous range of electromagnetic waves that vary from very short wavelengths to very long wavelengths. At one end of the spectrum, you have gamma rays, which have the shortest wavelengths and the highest frequencies. These are followed by X-rays, and then ultraviolet (UV) light.

As you move further along the spectrum, the wavelengths get longer and the frequencies get lower. After UV light comes visible light, which is the range of wavelengths that human eyes can detect. Visible light is followed by infrared radiation, which we often feel as heat.

Beyond infrared, you have microwaves, which are used for communications and cooking food. Finally, at the far end of the spectrum, you have radio waves, which have the longest wavelengths and lowest frequencies. These are used for broadcasting and various forms of communication. The spectrum is continuous, so there are no distinct boundaries between the different types of radiation; they blend smoothly into one another.

What is the order of the visible light spectrum?

The visible light spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. It consists of a range of colors, each with a different wavelength. The order of colors in the visible light spectrum, from longest wavelength to shortest, is as follows:

1. Red
2. Orange
3. Yellow
4. Green
5. Blue
6. Indigo
7. Violet

This sequence can be remembered by the acronym ROYGBIV. Red has the longest wavelength, and violet has the shortest. When light passes through a prism, it is split into its constituent colors, displaying the spectrum in this order. This phenomenon is known as dispersion. The visible light spectrum is a small part of the overall electromagnetic spectrum, which includes other types of waves such as radio waves, infrared radiation, ultraviolet light, X-rays, and gamma rays, which are not visible to the human eye.