This document outlines how the activity might be linked to the NGSS as part of a classroom lesson.
The below write-up is best designed for a high school-level chemistry class, not for elementary or middle school students, and it should be conducted by an experienced chemistry teacher. An alternative approach to this activity that can be conducted at the middle school level is to take a piece of nichrome wire and embed it in a wooden dowel. Prepare the same solutions as below except omit the methanol. Take the wire loop and heat it in a propane flame. Dip the wire loop in one of the metal salt solutions and then place the wet loop in the propane flame. The flame will take on a color characteristic of the element. Science Discipline(s) Chemistry Topics
- Forms of energy
- Physical properties
- Light transmission
- 5 liters Methanol
- 5 spray bottles (1/2 liter each)
- Bunsen burner
- 50 g lithium chloride
- 50 g copper sulfate
- 50 g sodium chloride
- 50 g potassium chloride
- 50 g magnesium sulfate
- 50 g Borax
- Protective gloves
- 5 Safety goggles
- Use gloves when preparing the salt solutions!
- Take 25 g of lithium chloride salt and add it to a ½ L pray bottle then fill the spray bottle with methanol, put the spray lid on the bottle and shake to dissolve the lithium chloride salt.
- Repeat step 2 for all five salts. For the copper sulfate solution, add 25 g of Borax for green color.
- Distribute the spray bottles to a group of 5 students and have them put on safety goggles.
- Ignite the Bunsen burner.
- Allow each student to spray their salt solution into the flame of the Bunsen burner (make sure the students don’t get too close to the flame and make sure they only spray the flame!).
- Rotate each salt solution amongst the 5 students so each of them get a chance to spray the 5 different salt solutions.
- Which variables are important in this activity? How could you design an experiment to test whether the variables are important?
- What kind of energy does the flame provide?
- What process takes place when metal salts emit light?
- Would you expect metal salts different from the metal salts we used to have the same flame colors? Why or why not?