Activity: Flame Test
Days Needed 1.5 Days
Grade level 9 - 12
Objective
Students will discover first hand how different elements
emit different specific wavelengths of light energy when burned, and that
these can be identified when the light is separated with a prism. |
Science and Math Standards
| NCTM |
NSES |
Content Standard 2:
- Mathematics as Communication |
Content Standard B:
- Abilities necessary to do scientific inquiry
- Understandings about scientific inquiry |
Content Standard 4:
- Mathematics as Connections |
Content Standard C:
- Structure of Atoms
- Interactions of energy and matter |
Content Standard 8:
Geometry from an algebraic perspective |
Content Standard G:
- Nature of Scientific Knowledge
- Historical Perspectives |
Prequisites
Math Students should have had some Pre-Algebra,
especially in the areas of manipulation of formulas and pattern recognition.
Science Students should have had an introduction to the
electromagnetic spectrum, the concept of a spectrum and how atoms emit
light energy.
Introduction
Recalling the characteristics of both atoms and light, the flame
test is a great way to physically demonstrate some of the more
abstract ideas discussed in the background sections on
Atoms and Light Energy and
Spectroscopy. |
Exploration
The students will work in lab groups of three to four students to
construct meaning on the causes of various light emissions from the
following 0.5M chemical solutions: LiCl, NaCl, CuCl, BaCl, CsCl, and CaCl.
To prepare for the Flame Test, each 0.5M solution should be placed in a test
tube by itself. Each of the six test tubes should then be placed at
the various laboratory stations 1 through 6. The students will rotate to
each station to test the solution.
Materials
7 test tubes
test tube rack
platinum wire or
wood splints
laboratory burner
goggles
apron
0.5M solutions of LiCl,
NaCl, CuCl, BaCl, CsCl and CaCl, and 1M of HCl.
Hand out the student worksheet. Have the students answer the thought questions
at the end of Part I in groups, but on paper. They should be utilized to
facilitate a meaningful discussion on light emission. Afterwards, the students
should complete the questions in Part II individually. They may be
assigned for homework if there is not enough class time.
Student Worksheet
Evaluation
Formative assessment and observation should be evident throughout the
lesson. The worksheet, final questions during closure or a future quiz may
serve as summative assessment.
Closure
Have students take three minutes to write in their own words why different elements
produce flames of different colors when burned. How is this quality useful in
astronomy?
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