Emission Spectrum - Online Tutor, Practice Problems & Exam Prep

Emission spectra are patterns of light produced when electrons transition from higher energy levels to lower ones within an atom, releasing energy. These spectra appear as distinct lines of color when the emitted light passes through a prism. The lines correspond to specific energy changes as electrons move between shells, with the final shell determining the type of spectrum. Electrons dropping to the first shell emit UV light (Lyman series), to the second shell emit visible light (Balmer series), and to third or higher shells emit infrared light (Paschen, Brackett, Pfund, and Humphrey series). These spectral lines are crucial for identifying atomic composition and understanding electron transitions within atoms.

Emission Spectrum

Now a mission Spectra is a series of lines formed when emitted light is focused by a slit and passes through a prism. Now here we have the representation of an atom in the middle. We have the nucleus with its protons and its neutrons, and we have our different shells. Here we have shell 1, shell two. And then here we have infinite number of possible shells for any given atom.

Now here we have our electron going from a higher shell back down to our shell #1. So we're going from a higher shell number to a lower shell number. This is emission and with emission we have the releasing of energy. So doing this transition would emit energy, and that energy can be emitted as light. The slit itself focuses that light and has it pass through a prism. Then that prism basically creates different colored lines on which we call an emission spectrum.

This emission Spectra can be used to determine what shells has the electron traveled through. Now we're going to say the slit is just a long narrow cut used to spread closely packed wavelengths which can later be determined. So the slit here is focusing the light and allowing us to separate it into these different bands of color. Now the prism itself. It transforms wavelengths into discrete lines on an emission Spectra.

Now with line of message elition Spectra we have each line of an emission Spectra is examined as a series of atomic emissions and realize that an atomic emission involves releasing energy as an electron goes from a higher shell number to a lower shell number. So with these emission lines we'll learn about what their names are and between what shells does the electron travel. So click on the next video and let's take a look at the different types of emission line Spectra.

Emission Spectrum

With atomic emission we have different line spectra that can be formed. Now with a line emission spectra it shows the energy released as electrons travel between different shells. So in this first grouping we have electrons going from a higher shell number, whether that be shells 2, 3, 4 or some unknown higher value. All of them end at shell #1, so they're all ending at the same place. So they're all going to fall within a certain general energy range. And here we're going to say if you're going from a higher shell number and ending at shell one, you're going to exist within the UV spectrum of the electromagnetic spectrum.

Now here, our next groupings, all of these, they start at some higher shell number and they go all the way down to shell two. When that happens, you belong to the visible light spectrum. And then finally, if you're going from a higher shell number and ending down at energy Level 3, then you would produce what we call infrared energy. Now remember, UV visible in IR are all parts of the electromagnetic spectrum. Now there are names attached to these different types of emissions. So we're going to say names of emission Spectra are based on the final shell reached by the electron.

So here we're saying that in the series you're ending at shell 1, 2, 3, 4, 5 and 6. We already said that if you're going from a higher shell number and ending at one, you'd exist within the UV or ultraviolet light spectrum. If you end at shell two, then you would fall within the visible light spectrum, and then if you end up at position or shell 3 through 6, then you would actually be in the infrared of the electromagnetic spectrum. Now, the names associated with these different types of emissions are your Lyman series. We have the Bommer series, the Passion series, we have the Bracket series, the Fund series, and the Humphrey series.

Yes, some of these names are weird. They're named after the individual responsible for their discovery, so that's why the names are all over the place. But just realize that as we go from a higher shell number to a lower shell number, that represents an emission. And depending on which shell you land on as your final destination, you exist as one of these different types of series, and maybe they'll be associated with either UV, visible or infrared energy.

Emission Spectrum Example 1

Here it says which of the following electron emissions corresponds to the bomber series of lines in the spectrum of a hydrogen atom. Right here it doesn't matter that it's dealing with a hydrogen atom. What's important is that we're dealing with a bomber series. Remember, in a bomber series we go from a higher shell number, which we can call Infinity, and our final destination is to land on shell #2, so we're landing on n=2.

So all we have to do is look and see which option shows us going from a higher shell number and stopping at shell #2 that represents A bomber series. So if we take a look at all the options, the only one that has a higher shell number ending at shell #2 will be option B.

In B we start off with the electron existing in shell #5 and then emits energy or light and drops back down to show #2. This represents A bomber series for an emission line Spectra.

Here’s what students ask on this topic:

What is an emission spectrum?

An emission spectrum is a unique spectrum of light frequencies emitted by an atom or molecule when it transitions from a higher energy state to a lower energy state. When an atom absorbs energy, its electrons jump to higher energy levels. As the electrons return to their original or lower energy levels, they release energy in the form of light. This light can be captured and spread out into a spectrum using a prism or a diffraction grating.

Each element has a characteristic emission spectrum, like a fingerprint, because the energy levels of electrons in atoms are quantized and unique to each element. When you observe the emission spectrum of an element, you'll see distinct lines at specific wavelengths, which correspond to the energy differences between the electron energy levels. These spectra are used in various applications, including identifying elements in stars and other celestial bodies, analyzing chemical compositions, and in neon lighting.

What is an atomic emission spectrum?

An atomic emission spectrum is a unique set of frequencies of electromagnetic radiation emitted by the electrons of an atom as they transition from a higher energy level to a lower one. Each element has its own distinctive emission spectrum, which is like a fingerprint for that element. When an atom absorbs energy, its electrons can jump to higher, less stable energy levels. Eventually, these electrons will return to their more stable, lower energy levels, and in doing so, they release the absorbed energy in the form of light. This light can be split into its component wavelengths, creating a spectrum.

The resulting spectrum consists of a series of lines, known as spectral lines, and each line corresponds to a specific wavelength of light emitted by the atom. These lines are indicative of the energy differences between the energy levels of the electrons. Atomic emission spectra are used in various applications, including identifying elements in stars and distant galaxies, analyzing the composition of materials, and in forensic science for identifying substances.

How do you read an emission spectrum?

Reading an emission spectrum involves analyzing the light emitted by an element or compound when it is excited. Here's how to do it:

1. Identify the Background: Emission spectra are typically displayed against a dark background with bright lines. These lines represent the wavelengths of light emitted.
2. Recognize the Lines: Each bright line in the spectrum corresponds to a specific wavelength of light. These lines are unique to each element, much like a fingerprint.
3. Understand the Colors: If the spectrum is in color, you'll see lines ranging from violet to red. Each color represents a different energy level; violet has the highest energy and red has the lowest.
4. Use a Wavelength Scale: There should be a scale, usually in nanometers (nm) or angstroms (Å), indicating the wavelength of the emitted light. Match the lines to the scale to determine their wavelengths.
5. Compare with Known Spectra: To identify the element or compound, compare the observed spectrum with known emission spectra. Each element has a characteristic pattern of wavelengths it emits.
6. Consider the Intensity: The brightness of the lines can give you information about the abundance of the element in the sample or the conditions under which the sample was excited.

By examining these aspects, you can interpret what elements are present in the source of the emission.