Spectroscopy
Subject Area(s) Waves and Electromagnetic Radiation, Structure and Properties of Matter, Energy
Associated Unit Atoms, Atomic Structure and Electron Configuration
Lesson Title Spectroscopy
Public
Figure 1
Domain
ADA Description: The image is of visible light from violet to blue, green, yellow, orange and red. Various
bright vertical lines in the image represent the bright-line emission spectra of Helium gas. Each element or
compound has a unique spectral “fingerprint”.
Source/Rights: Copyright © "Helium spectrum" by NASA http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/worksheet-specgraph2-sol.html. Licensed
under Public Domain via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Helium_spectrum.jpg#/media/File:Helium_spectrum
.jpg
Caption: Bright-line Emission Spectra of Helium
Grade Level
9-12
Time Required
2 hrs.
Summary
“Spectroscopy” is a laboratory activity requiring some specialized equipment readily available from science
supply vendors. The specialized equipment involved are spectrum tube power supplies, spectrum tubes of
various elements or compounds, such as oxygen, helium, hydrogen, water vapor, etc. and spectroscopes.
Alternatively, students could design and construct a simple spectroscope, if a diffraction source is provided.
Additional supplies include colored pencils and paper or a lab recording book. Students view and draw the
spectra of various elements with bright lines at specific wavelengths (nm) and use their data to identify 2
unknowns. The spectral lines have significance in understanding quantum theory, electron configurations,
electron energy, and the electromagnetic spectrum.
Engineering Connection
Many applications exist for spectroscopy today. Astronomers use visible light spectra to identify the elements
and compounds in distant bodies. Engineers are constantly working on new devices to use spectra of both visible
light and a range of other wavelengths such as ultraviolet, terahertz, and others in order to identify quickly and
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cheaply compounds for a variety of applications. These applications include using terahertz spectroscopy to
identify volatile organic compounds (VOC) in human breath for medical applications and to identify potential
explosives for security operations. Spectroscopy can be used to both identify and learn something about the
structure of matter. The students may also design and build their spectroscopes as an additional engineering
connection.
Engineering Category =
Relating science and/or math concept(s) to engineering.
Keywords
Spectroscopy, spectrum, bright-line emission spectrum, spectroscope, energy level, excited state, ground state,
wavelength, light, electromagnetic spectrum.
Educational Standards (List 2-4)
Engineering Standard
HS-ETS1-2. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems
that can be solved through engineering.
HS.Waves and Electromagnetic Radiation
Students who demonstrate understanding can:
HS-PS4-1. Use mathematical representations to support a claim regarding relationships among the frequency, wavelength,
and speed of waves traveling in various media
HS-PS4-3. Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described
either by a wave model or a particle model, and that for some situations one model is more useful than the other.
HS-PS4-5. Communicate technical information about how some technological devices use the principles of wave behavior
and wave interactions with matter to transmit and capture information and energy.
Math Standards
MAFS.7.SP.1.2
MAFS.912.S-IC.1.2
Use data from a random sample to draw inferences
about a population with an unknown characteristic of
interest. Generate multiple samples (or simulated
samples) of the same size to gauge the variation in
estimates or predictions.
Decide if a specified model is consistent with results
from a given data-generating process, e.g., using
simulation.
Science Standards
MAFS.912.S-IC.2.5
Language Arts Standards
LAFS.910.W.1.1
Use data from a randomized experiment to compare
two treatments; use simulations to decide if differences
between parameters are significant. Cognitive
Complexity: Level 2: Basic Application of Skills &
Concepts
Write arguments to support claims in an analysis of
substantive topics or texts, using valid reasoning
and relevant and sufficient evidence.
a. Introduce precise claim(s), distinguish the
claim(s) from alternate or opposing claims, and
create an organization that establishes clear
relationships among claim(s), counterclaims,
reasons, and evidence.
b. Develop claim(s) and counterclaims fairly,
supplying evidence for each while pointing out the
strengths and limitations of both in a manner that
anticipates the audience’s knowledge level and
concerns.
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c. Use words, phrases, and clauses to link the major
sections of the text, create cohesion, and clarify the
relationships between claim(s) and reasons,
between reasons and evidence, and between
claim(s) and counterclaims.
d. Establish and maintain a formal style and
objective tone while attending to the norms and
conventions of the discipline in which they are
writing.
e. Provide a concluding statement or section that
follows from and supports the argument presente
LAFS.910.W.1.2
LAFS.910.W.2.4
LAFS.910.SL.2.4
Write informative/explanatory texts to examine and
convey complex ideas, concepts, and information
clearly and accurately through the effective
selection, organization, and analysis of content.
a. Introduce a topic; organize complex ideas, concepts, and information to mak
important connections and distinctions; include formatting (e.g., headings), gra
(e.g., figures, tables), and multimedia when useful to aiding comprehension.
b. Develop the topic with well-chosen, relevant, and sufficient facts, extended
definitions, concrete details, quotations, or other information and examples
appropriate to the audience’s knowledge of the topic.
c. Use appropriate and varied transitions to link the major sections of the text,
create cohesion, and clarify the relationships among complex ideas and conce
d. Use precise language and domain-specific vocabulary to manage the comp
of the topic.
e. Establish and maintain a formal style and objective tone while attending to th
norms and conventions of the discipline in which they are writing.
f. Provide a concluding statement or section that follows from and supports the
information or explanation presented (e.g., articulating implications or the
significance of the topic).
Produce clear and coherent writing in which the
development, organization, and style are
appropriate to task, purpose, and audience.
Present information, findings, and supporting
evidence clearly, concisely, and logically such that
listeners can follow the line of reasoning and the
organization, development, substance, and style
are appropriate to purpose, audience, and task.
Pre-Requisite Knowledge
Students should have been introduced to the concepts of the electromagnetic spectrum, waves, light, refraction,
diffraction and spectroscopy. Additionally, students should be familiar with quantum theory, electron
configurations, and how electrons moving from ground state to excited state and back to ground state produce
electromagnetic waves of varying wavelength and frequency.
Learning Objectives
After this lesson, students should be able to:
 Describe bright-line emission spectra for various elements and compounds.

Use bright-line emission spectra to compare the spectra of known substances to unknown substances
in order to identify the unknown substance.

Explain the relationship between wavelength and color of visible light.
Introduction / Motivation
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Electrons can become excited and change energy levels. The light given off is a property for the
particular atom of an element. A spectroscope is an instrument which contains a prism or diffraction
grating which can separate light into specific energies or wavelengths. An early spectroscope is shown
in Fig.3. The wavelengths are commonly known as colors (Fig. 2). All the colors for a particular
substance make up its spectrum. Sunlight gives a complete spectrum or rainbow. Excited electrons of
atoms of elements give a bright-line emission spectrum. It was this bright-line spectrum which led
Neils Bohr to his discovery of the quantum theory. In addition to studying atomic structure, spectra can
be used by astronomers to infer the composition of distant bodies such as stars and planets. Chemists
often vaporize materials and then use the spectrum to help identify the makeup of a sample (Fig. 1).
Spectroscopy may use wavelengths of light outside the visible range. Engineers are constantly working
on new devices to use spectra of both visible light and a range of other wavelengths such as ultraviolet,
terahertz, and others in order to identify quickly and cheaply compounds for a variety of applications.
These applications include using terahertz spectroscopy to identify volatile organic compounds
(VOC’s) in human breath for medical applications and to identify potential explosives for security
operations. VOC’s are associated with certain medical or health conditions. Elevated levels of
compounds like ethane and acetylaldhyde can be measured as an indicator of disease potential. Various
VOC’s are known to be associated with conditions such as diabetes, kidney problems, and lung and
liver disease among many others. VOC’s even have potential to help doctors know when the body is
rejecting transplanted organs much earlier than is now possible. Ultra violet spectroscopy may also
have application in medicine, such as measuring Cortisol levels. Cortisol is a hormone associated with
stress. Thus spectroscopy is an important tool for chemist, physicist, and engineers and is used in
almost all university and industry laboratory settings.
Lesson Background & Concepts for Teachers
Spectroscopy is a very useful method found in almost all university and industrial chemistry
laboratories. In its simplest form, visible light spectroscopy, spectroscopy can easily be achieved in the
classroom. In order to understand how spectroscopy works, one must understand something about the
nature of light, waves, and quantum theory.
Scientists have shown that all matter, like light, has properties of both waves and particles. Of the three
well known fundamental particles found in atoms, protons, neutrons, and electrons, electrons in
particular, are important in our understanding of the behavior and structure of matter and how
spectroscopy works. Niels Bohr while studying the simplest atom, hydrogen (1 proton and 1 electron,
no neutrons), discovered that electrons could only have discrete amounts of energy, known as quanta.
An electron’s energy is correlated with its distance from the nucleus of the an atom, much like a ball
gains gravitational potential energy as it is moved up a hill, because the positive nucleus pulls on the
negative electron. By much complicated math and various experiments it was demonstrated that four
mathematical functions were needed to describe the region of space around the nucleus where an
electron is likely to be found. These are known as quantum numbers. The first quantum number is
known as the energy level quantum number (n) and describes the distance if an electron from the
nucleus of the atom. The second quantum number, the sublevel quantum number (l), describes the
shape of the region of space around the nucleus. The third quantum number, the magnetic quantum
number (m), describes the orientation of the sublevel around the nucleus (See Figure 4) and the final
quantum number, the spin quantum number (ms) describes the electrons spin (much like the little
planets) which may be clockwise or counterclockwise. Interestingly, the pattern of the periodic table,
discovered well before quantum theory, matches well to the first two quantum numbers (7 rows for 7
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Figure 2
Description
The Electromagnetic Spectrum
Inductiveload, NASA - self-made, information by NASA Based off of File:EM_Spectrum3new.jpg by NASA The butterfly icon is from the P icon set, P biology.svg The humans are
from the Pioneer plaque, Human.svg The buildings are the Petronas towers and the Empire
State Buildings, both from Skyscrapercompare.svg
A diagram of the Milton spectrum, showing the type, wavelength (with examples), frequency,
the black body emission temperature. Temporary file for gauging response to an improved
version of this file. Adapted from EM_Spectrum3-new.jpg, which is a NASA image.
Permission details
Permission is granted to copy, distribute and/or modify this document under the
terms of the GNU Free Documentation License, Version 1.2 or any later
version published by the Free Software Foundation; with no Invariant Sections,
no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is
included in the section entitled GNU Free Documentation License.
Version July 2015
This file is licensed under the Creative Commons AttributionShare Alike 3.0 Unported license.
5
You are free:
Figure 3
Description
Solar automatic spectroscope of John Browning c.1831-1925
Date
20 April 2012
Source
[ How to Work With the Spectroscope]
Author
Artist unknown; Author and Publisher John Browning 1878
This media file is in the public domain in the United States. This applies to U.S. works where the
copyright has expired, often because its first publication occurred prior to January 1, 1923.
energy levels, 4 major blocks for 4 sublevels). This is due to the fact that the valence (outermost)
electrons determine most of the chemical properties of elements.
An electron in its lowest possible energy state is said to be in its ground state. If an atom absorbs
energy (heat, light, electrical, etc.), electrons may absorb energy and move temporarily further from the
nucleus into an excited state. Due to the laws of entropy, all things in nature, including electrons, tend
to the lowest energy state over time. As an electron returns to the ground state from the excited state,
the excess energy is emitted as a photon of light. This is in fact, the source of all known light and
electromagnetic radiation. The electron’s change in position, its energy and the distance it moves give
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the light characteristic wavelengths and frequencies. In the visible range (wavelengths between
approximately 400 nm and 700 nm), we experience these wavelengths as the various colors of the
rainbow. Studying this light tells us much about the matter from which it comes and spectroscopy
provides a useful technique for doing so.
Most of us are familiar with the way a prism bends and separates colors of light by refraction.
Raindrops may act in this capacity producing a rainbow. Diffraction is another method that produces
similar results. When waves pass through small openings, the edges of the waves slow down, causing
the waves to bend. This is known as diffraction. A series of small openings is known as a diffraction
grating (Fig. 5).
The waves beyond the diffraction grating overlap each other and interfere with one another. Where a
crest meets a trough, the wave is reduced or canceled temporarily (destructive interference). Where a
crest meets a crest or a trough meets a trough the wave is built up (constructive interference). This
interference pattern will cause the various wavelengths not only to separate, but to form a pattern; for
light, a pattern of bright lines like the one in Figure 1, known as a bright-line emission spectra. The
dark areas correspond to destructive interference and bright areas to constructive interference. These
patterns are directly related to the quantum nature and unique energies of electrons within the atom. A
spectroscope takes advantage of these properties to separate light and produce these patterns.
A simple spectroscope is nothing more than a tube with an opening to look through at one end and a
diffraction grating on the other. These can be purchased cheaply from science supply companies or
made from diffraction grating sheets (even cheaper from science supply companies) and paper roll
tubes or even cereal boxes and CD’s. Some teacher’s may find it an advantage to give the students the
experience of constructing their own spectroscopes while others may prefer the convenience of readymade ones. An online search will reveal how to make or purchase spectroscopes, as well as power
supplies and spectrum tubes (tubes containing various gases, each with a unique bright-line spectrum).
Alternatively, sunlight is always available and fluorescent bulbs contain mercury. Many street lamps
contain sodium and older incandescent bulbs use tungsten filaments. When light shines through the
diffraction grating, it is separated into its varying wavelengths or colors caused by the electrons
previously described. See Figure 1 for the spectra of helium gas, He, Figure 6 for hydrogen gas, H2.
Note that sunlight will give a full, continuous spectra of all the visible colors rather than the bright-line
emission spectrum such as that in Figure 1. The pattern of the lines is unique for each source, much
like a light “finger print” and can be used to identify the source by comparing to known sources. This
is how astronomers, for example, infer the composition of distant bodies and is also the premise of this
laboratory activity. It is suggested that the instructor provide a number of known sources and one or
two sources whose identify has been hidden, the “unknowns”. The student’s goal is to identify these
unknowns correctly. Of course the unknowns must repeat the known sources and I have found that this
needs to be made clear to students in order to avoid confusion. Each of the” unknowns” will be the
same as one of the “knowns” in the lab. See the data table below. The blank lines of the data table are
for the students to write in the names of any sources you provide other than sunlight, fluorescent light
and the unknowns. The scale on the data table is in nanometers (nm). Most purchased spectroscopes
will include a similar scale. If you make your own spectroscopes, the scale may still be useful. Use
sunlight as a control and line up the red end of the rainbow with 700 nm and the violet end with 400
nm. Spread the other colors evenly between them, just as you observe and your wavelengths will be at
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Figure 4
Description Three quantum numbers, n, l, and m, describing the movements of electrons
around atoms. The nucleus of the atom would be at the center of these images of
the electron clouds representing the various orbital shapes (m). n= 1 is the first
energy level, n= 2 is the second, etc. s, p, d, and f represent the sublevels (l). As
an atom gets larger and more electrons are added, more sublevels and orbitals are
filled moving outward. For example, the orange in the center of n= 1 and the s
sublevel represents the entire orbital shown in n= 1, s sublevel surrounded by the
n= 2 s sublevel.
Date
18:13, 2 April 2007
Source
his work is licensed under the Creative Commons Attribution-ShareAlike 3.0
License. This licensing tag was added to this file as part of the GFDL licensing update.
least approximately correct. Each spectrum should be drawn to scale. The scale seems reversed
Author
Kozicki spectroscopes in my lab come that way. You can reverse the
below,
becauseJanek
the commercial
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numbering easily enough if so desired. Referring to Figure 1, I tell the students to draw the bright
lines only and ignore the fainter colors in the background which are often caused by light leakage and
in any event do not provide any useful information. Only for the sunlight control are they to draw a full
spectrum (rainbow). Having them only draw lines of color will also save much time, as they tend to get
carried away and take longer than necessary.
More complex forms of spectroscopy, using not only light, but other parts of the electromagnetic
spectrum are used in many applications; more than can possibly be covered here.
Figure 5
Description A two slit diffraction grating showing wave interference and diffraction.
Date
23 February 2010, 15:02 (UTC)
Source
Doubleslitdiffraction.png. This file is licensed under the Creative Commons
Attribution-Share Alike 3.0 Unported license. Subject to disclaimers.
Author


Doubleslitdiffraction.png: Bcrowell
derivative work: Quibik (talk)
Lesson
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Problem: “Can bright-line emission spectra be used to identify a gas?”
Independent variable: bright-line emission spectra
Dependent variable: identity of unknown substance
Have the students write a hypothesis.
MATERIALS (Figure 7)
Power supplies
Gas tubes (light sources)
Spectroscopes
PROCEDURE
1. Examine the spectroscope. Locate the viewfinder and the diffraction grating (small slit
opposite the viewfinder).
2. Aim the spectroscope at a natural light source in order to practice its use. Look through
the viewfinder.
3. Rotate the spectroscope, until the spectrum and scale are clearly visible. You must line
the slit up with the light source. The scale in thousands of nanometers and represents the
wavelength of the light.
4. Observe sunlight (white light) first. The spectrum of white light should be a continuous
rainbow with no gaps in it.
5. Draw the white light spectrum including the scale and line the colors up with their correct
wavelengths.
6. Observe mercury (Hg) using the fluorescent ceiling bulbs and label and draw its brightline spectrum on the chart. Draw only the bright lines, not the background colors the may
bleed in from other light sources.
7. Go to each station and label and draw the spectrum for each element. Be sure to put the
chemical symbol or formula on your data table each time.
8. Repeat step 7 for the two unknowns and try to identify them based on their spectra.
RESULTS AND DATA
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Element/Compound
from Light Source
Spectral Colors, Bright-line Pattern, and Wavelengths (100 nm)
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
Sunlight
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
Hg from fluorescent
bulb
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
Unknown 1
7
6
5
4
liiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiiliiiil
Unknown 2
7
6
5
4
DISCUSSION AND ANALYSIS
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1. What causes the spectral lines?
2. How does a gas spectrum compare to your fingerprints?
3. Discuss whether or not your hypothesis was supported and why.
4. What is unknown 1? How do you know?
5. What is unknown 2? How do you know?
6. Look up some uses of refracting or diffracting in bright-line spectra and describe several.
7. Complete this question if all three compounds are available only: Compare the spectra of
H2, O2, and H2O. How do they compare and why do you think this is so?
Figure 6
Description A depiction of the Hydrogen emission lines from 400nm to 700nm
Date
17 October 2009
Source
Own work with information taken from NIST
Author Jkasd
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons
Attribution 3.0 Unported license.
You are free:

Vocabulary / Definitions
Word
Bright-line emission
spectrum
Version July 2015

to share – to copy, distribute and
transmit the work
to remix – to adapt the work
Definition
The distribution
of electromagnetic
radiation released by a substance
Under
the following conditions:
whose atoms have been excited by heat or radiation. A spectroscope
 attribution
You must attribute
the emitted by a
can be used to determine
which –frequencies
have been
work
in
the
manner
specified
by
the
substance. See Fig. 1.
author or licensor (but not in any way
that suggests that they endorse you or
your use of the work).
12
diffraction
Diffraction grating
Electromagnetic
spectrum
Electron
Electron configuration
Energy level
Excited state
Ground state
Light
Various phenomena which occur when a wave encounters an obstacle
or a slit. In classical physics, the diffraction phenomenon is described
as the interference of waves.
In optics, an optical component with a periodic structure, which splits
and diffracts light into several beams travelling in different directions.
The emerging coloration is a form of structural coloration.
The range of all possible frequencies of electromagnetic radiation. See
Fig. 2. The "electromagnetic spectrum" of an object has a different
meaning, and is instead the characteristic distribution of
electromagnetic radiation emitted or absorbed by that particular object.
The electron is a subatomic particle, symbol e− or β−, with a negative
elementary electric charge. Electrons belong to the first generation of
the lepton particle family, and are generally thought to be elementary
particles because they have no known components or substructure.
In atomic physics and quantum chemistry, the electron configuration
is the distribution of electrons of an atom or molecule (or other
physical structure) in atomic or molecular orbitals. For example, the
electron configuration of the neon atom is 1s2 2s2 2p6, where the ‘1’ is
the energy level, the ‘s’ is the sublevel, and the superscript ‘2’ is the
number of electrons in that sublevel. The pattern repeats for each
remaining set of numbers and letters.
The fixed amount of energy that a system described by quantum
mechanics, such as a molecule, atom, electron, or nucleus, can have.
For electrons, the energy level is related to the distance the electron
travels from the nucleus of the atom.
In quantum mechanics an excited state of a system (such as an atom,
molecule or nucleus) is any quantum state of the system that has a
higher energy than the ground state (that is, more energy than the
absolute minimum).
The ground state represents the minimum energy an electron can have
(the particular electron cannot be any closer to the nucleus). After
absorbing energy, an electron may jump from the ground state to a
higher energy excited state.
Light is electromagnetic radiation within a certain portion of the
electromagnetic spectrum. The word usually refers to visible light,
which is visible to the human eye and is responsible for the sense of
sight. Visible light is usually defined as having a wavelength in the
range of 400 nanometers (nm), or 400×10−9 m, to 700 nanometers –
between the infrared (with longer wavelengths) and the ultraviolet
(with shorter wavelengths). Often, infrared and ultraviolet are also
called light.
Nanostructure
A structure, especially a semiconductor device that has dimensions of
only a few nanometers (10-9 or one billionth of a meter).
Quantum state
In physics, discrete bundles in which radiation and other forms of
energy occur. For example, in the Bohr atom, light is sent out in
quanta called photons.
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Quantum theory
Spectroscope
Spectrum
Terahertz radiation
(THz)
Terahertz spectroscopy
Ultraviolet light
Visible light
Volatile organic
compounds (VOCs)
wavelength
Quantum theory is the theoretical basis of modern physics that
explains the nature and behavior of matter and energy on the atomic
and subatomic level. The nature and behavior of matter and energy at
that level is sometimes referred to as quantum physics and quantum
mechanics.
An optical spectrometer (spectrophotometer, spectrograph or
spectroscope) is an instrument used to measure properties of light
over a specific portion of the electromagnetic spectrum, typically used
in spectroscopic analysis to identify materials.
A spectrum (plural spectra or spectrums) is a condition that is not
limited to a specific set of values but can vary infinitely within a
continuum. The word was first used scientifically within the field of
optics to describe the rainbow of colors in visible light when separated
using a prism. As scientific understanding of light advanced, it came
to apply to the entire electromagnetic spectrum.
In physics, terahertz radiation – also known as submillimeter
radiation, terahertz waves, tremendously high frequency, T-rays, Twaves, T-light, T-lux or THz – consists of electromagnetic waves
within the ITU-designated band of frequencies from 0.3 to 3 terahertz
(THz; 1 THz = 1012 Hz). Wavelengths of radiation in the terahertz
band correspondingly range from 1 mm to 0.1 mm (or 100 μm),
between microwaves and infrared.
Terahertz spectroscopy detects and controls properties of matter with
electromagnetic fields that are in the frequency range between a few
hundred gigahertz and several terahertz. THz spectroscopy has
applications in nanostructure design, exploring the properties of large
molecules, and many other potential, but undeveloped uses.
Ultraviolet (UV) light is an electromagnetic radiation with a
wavelength from 400 nm to 100 nm, shorter than that of visible light
but longer than X-rays.
See “light” definition.
Volatile organic compounds (VOCs) are organic chemicals that
have a high vapor pressure at ordinary room temperature. Their high
vapor pressure results from a low boiling point, which causes large
numbers of molecules to evaporate or sublimate from the liquid or
solid form of the compound and enter the surrounding air.
The distance between successive crests of a wave, especially points in
a sound wave or electromagnetic wave.
Associated Activities
I recommend teaching on waves, electrons, spectroscopy and quantum theory using a variety of teaching
methodologies.
Lesson Closure
Discuss the results in their lab groups and make a very brief presentation to the class on a white board or 3 slide
PowerPoint in addition to their lab reports. The slides could be in the format: Claim, Results, and Explanation.
Assessment
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I have my students do a complete lab report which covers all the assessments below. We than
exchange lab books and score the lab reports using a rubric. A suggested format is shown on the next
page.
Spectrum Tube
Power Supply
Spectroscope
http://www.flinnsci.com/
Figure 7
Description Spectroscopes, power supplies and spectrum tubes, all purchased from Flinn
Scientific.
Date
July 2015
Source
Mark Silverman
These are my own photos and have no copy write.
High School Science Lab Report Format
Title
The title should be descriptive of the laboratory investigation conducted. Underline the title.
A conclusion statement answers the following questions in at least three paragraphs
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Abstract
Summary Paragraph for the entire lab.
 State the problem.
 Summarize what you did, that is summarize your procedure in one sentence.
 State the hypothesis
 Tell whether the hypothesis was supported and why or why not.
Introduction
The introduction must be short and precise:
Background
The Introduction must have background information pertaining to the laboratory. This
requires research and should contain citations in quotes with the source author’s last name
and the date of publication immediately afterward in parenthesis.
Problem Statement Briefly state the purpose or Problem Statement. When writing the purpose you should ask
yourself: “What am I trying to show, find or do?”
Variables & Control Independent (Manipulated) Variable: what is changed or tested?
Dependent (Responding) Variable: what is affected by the change?
Control (Constants): what remains the same throughout experiment?
Hypothesis
Write your hypothesis using one of the following formats:
 If cause then effect.
 If the variable is applied then this result will be observed.
 I predict…
 I hypothesize…
Be sure to include the independent and dependent variables in your hypothesis!
Materials
List the name, size, type of units, and quantity of the equipment and materials used in lab.
Procedures
List the steps performed in your lab, in your own words. Steps MUST be in the correct order.
Sometimes if given permission, you can summarize the procedure from a handout.
Data
(Observations)
All descriptive (Qualitative) information and numerical (Quantitative) information
goes in this section. For example: graphs, data tables, math calculations, and written
observations.
Data Analysis
(Results)
Use words and math (mode, median, mean or average, range, percents, etc.) to analyze
describe your data.
Conclusion
Answer any questions provided in the lab or by the teacher.
Citations
Write a bibliography for the sources you used in your pre-lab research based on the following
examples:
GOODMAN, HARVEY, LINDA E. GRAHAM, THOMAS C. EMMEL, FRANCIS SLOWICZEK, AND YAAKOV
SCHECHTER. 1989. Biology. Harcourt, Brace, and Jovanovich, Publishers, Orlando, Florida. Chapter 2:
“Science and Problem Solving.”: 24-28.
ZOOLOGY SOCIETY. URL: http://www.zoologysociety.org/usa/lobster1.htm.
Lab Report Rubric
Part of Report
Brief Description
Maximum Points
Points Earned
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Title
Descriptive title of the lab
investigation conducted.
5
Abstract
A conclusion summarizes what
happened in the experiment. It
needs to accept or reject your
hypothesis and answer your
problem statement. Should also
be written in essay format.
15
Introduction: Background
Briefly states the purpose or
problem statement. Includes
background information
pertaining to the laboratory.
10
Identify the factors that may
change in the laboratory; such as
independent variable, dependent
variable, constants and control.
5
Introduction: Hypothesis
Consists of a statement that
predicts the outcome of the
experiment. Use the “If…
then….” statement format.
5
Materials
List that includes the name, size,
type of units, and quantity of the
equipment and materials used to
do the lab.
5
Procedures
List that outlines the steps
performed in your lab, in your
own words. Make sure they are
in the correct order.
5
Data (Observations)
Include descriptive (Qualitative)
information such as observations
and numerical (Quantitative)
information (graphs, data tables,
math calculations).
15
Data Analysis (Results)
Use words and math (mode,
median, mean or average, range,
percents, etc.) to analyze and
describe (Results) your data.
10
Conclusion
Questions about the lab.
20
Citations
A Proper Bibliography of
sources, both books and internet.
5
Total
Total the points earned
and Problem Statement
Introduction:
Variables & Control
100
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Contributors
Mark Silverman
Supporting Program
Research Experience for Teachers (RET), Florida International University Engineering Center
Acknowledgements
Thank you to Dr. Milani Masoud, Stephanie Strange, Kerlyn Prada, Dr. Nezih Pala, Kirin, Sirca, Masoud and all
the other hard working people at FIU Engineering for your support and assistance. Also, for her patience, my lab
partner Irina.
Classroom Testing Information
This STEM activity is designed for a high school science course and can be used as part of the curriculum to
prepare students for the Chemistry End of Course Exam (EOC). The activity could easily be simplified and
adapted to middle school physical science as well.
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