Examining a Trend in the Periodic Table of Elements

Research Questions:

• What do you think will happen as you go down the column of alkaline earth metals?
• What do you think would happen if you went to the first column of the periodic table?
• Do you notice a trend that could apply to the whole periodic table?

Materials:

• ~0.1 piece of lithium
• Magnesium
• Calcium
• Strontium turnings
• 50mL graduated cylinder
• 5- 100mL beakers
• Mass balance
• 3- 50mL beakers
• Timer
• Vinegar
• Universal indicator solution
• De-ionized water
• Tweezers
• 3 Volunteers

Experimental Procedure:

1. Measure 35mL of de-ionized water into each of the three 50mL beakers.
2. Add 20 drops of universal indicator and 5 drops of vinegar to all three beakers. Swirl the solution to mix.
3. Place 2 large pieces of calcium into the first 100mL beaker.
4. Place 2 similar sized pieces of magnesium into the second 100mL beaker.
5. Place 2 similar sized pieces of strontium into the last 100mL beaker.
6. One person should be ready to time this next step.
7. Each of the 3 volunteers should get ready to pour the vinegar solution into each of the beakers at the same time.
8. The timing person should record the time it takes each beaker turns purple.
9. If one element takes longer than 5 minutes, stop the time and write down 5+.
10. You should now know which element reacts the fastest, faster, and slowest. With this data, look back at and answer the research questions.

Terms/Concepts: Reactivity, Alkaline-Earth Metals, Alkaline Metals, Periodic Table of Elements

References:

Reactivity: http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/react1.htm

Alkaline- Earth Metals: http://www.chemicalelements.com/groups/alkaline.html

Alkaline Metals: http://www.carondelet.pvt.k12.ca.us/Family/Science/Alkali%20Metals/