Lab 7: Flame Test Lab

In the flame test lab, we used wooden popsicle sticks soaked in various compounds made of a metal + chloride and placed them over a flame in order to see the color of light emitted. The loosely held electrons of the metals were excited by the flame, which then caused the electrons to release a certain color of light when they returned to their ground state. We also had to test two unknown compounds, see what colors were emitted, and identify the compounds.

1. What is the difference between ground state and an excited state?

The ground state is when the electrons are in their normal configuration. The excited state is when some electrons absorb energy and jump to a higher energy level.

2. What does the word "emit" mean?

The word emit means to produce or release. Electrons emit light in the form of electromagnetic radiation when they fall back to the ground state after being excited.

3. In this experiment, where are the atoms getting their excess energy from?

The atoms are getting excess energy from the flame that the metals are held over. Without the flame, the electrons would not get excited, and the light released would be much weaker.

4. Why do different atoms emit different colors of light?

Different atoms emit different colors of light because each atom is quantized, meaning each atom will only produce one certain color, and none in between. Different atoms also means that they have different numbers of electrons, which leads to different energy levels. The electrons of one atom could be able to jump and then fall from the fourth level to the second, emitting one color, while another atom's electrons might jump then fall from the third level to the second, emitting a different color.

5. Why is it necessary to clean the nichrome wires between each flame test?

It is necessary to clean the wires/use different wooden sticks between each flame test because otherwise, the flame will react with both compounds. This would confuse the viewer as to which color corresponds to which compound.

Above are pictures of the color produced by NaCl, a selfie of me and my lab partner holding one of the wooden sticks, and the color produced by LiCl

Unknown #1: LiCl - We know Unknown #1 is LiCl because it produced a bright fuchsia/red color that looked exactly like the color produced by LiCl.

Unknown #2: KCl - We know Unknown #2 is KCl because it produced a light purple color that looked exactly like the color produced by KCl.