Flame Test Lab

1. Flame Test Lab 8th Grade Science Mrs. Dainty

2. Review • Can we define the following terms? • Atom • Element • Metal • Compound • Bunsen Burner • Physical Characteristic • Chemical Characteristic • Energy Levels • Light

3. Background • When certain metal compounds, or metal salts, are heated, their electrons enter an excited state. • In this excited state, electrons move from lower energy levels to higher energy levels. • This excited state is unstable, so the electrons quickly return to their lower energy levels. When this happens, the lose energy in the form of LIGHT. • When this light is in the visible range, we can see it. (Remember Roy G. Biv!)

4. Background • Flame tests can be conducted to determine the identity of unknown elements. • Certain elements give off known colors of light. These can be compared with the color of light given off by an unknown substance.

5. Your Job: • Your mission is to discover what metal elements are present in a dehydrated banana by conducting a flame test. • First, you will discover the colors given off by: • Calcium Chloride • Copper Chloride • Lithium Chloride • Potassium Chloride • Sodium Chloride • Strontium Chloride • Then, you will test a banana to see if any color change occurs in the flame. Compare these results to the known elements to draw conclusions about what’s in the banana!

6. Limitations • The flame test may not detect atoms that are present in low concentrations. • The flame test cannot distinguish between ALL elements. (Some elements create the same color. Some elements don’t create a visible change in the flame color at all.) • Impurities and contaminates can affect your results.

7. Science Notebook • In your notebook, write a title and date for this lab. • Next, write the question we’re investigating in your own words. Your questions should make it very clear what we are trying to learn, and should identify any variables being tested. • Finally, make a prediction. (I think that…because…)

8. Demonstration • Flame test demonstration: • 1st time – watch and listen • 2nd time – write a materials list and procedures

9. Safety Considerations • Utmost care must be taken during this lab. Absolutely no goofing around will be tolerated. • Minimize movement around the room, as well as talking with your hands! (Materials Manger only one to walk around to get supplies.) • Goggles, gloves, and lab coats are to be worn. • Long hair must be tied back. • Know locations of emergency equipments: eye wash, shower, fire blanket, fire extinguishers, etc. • Voices should be kept low. • In case of emergency, the FIRST thing you do is to find your teacher! • Follow instructions for disposal of chemicals.

10. Science Notebook • Once you have written down the materials and procedures, develop a table in your results section. • You must have your table ready before you can begin the lab. • Chemicals you’ll test: • Calcium Chloride • Copper Chloride • Lithium Chloride • Potassium Chloride • Sodium Chloride • Strontium Chloride • Unknown (Banana)

11. Lab Day Lab Groups: Non-Lab Groups: Get goggles. Choose a place to sit near the windows. DO NOT SIT BY ANYONE WHO WILL TEMPT YOU TO GOOF OFF. My attention needs to mainly be with lab groups and I will have little patience for goofing around today! Work: Ch. 3, Lesson 4 If finished, can take turns “building an element.” (Further instructions to come.) • Get goggles, gloves, and lab coats. • Place books at tables near sinks. Bring ONLY lab notebooks to work station at counter. • Go to your designated lab station. Clear away unneeded materials. Designate group roles. (If only 3, share spokesperson responsibilities.) • Wait for permission to begin.