Summer SAVY Session 2, Day 3 – Common and Practical Chemistry (Pao)
Day 3: Today, we learned about ionic and covalent bonds and reviewed concepts from previous days. In order to review polarity, acids, and bases, students made alka-seltzer “lava lamps”, where they saw interactions between oil (nonpolar) and water (polar), as well as the acid-base reaction from the alka-seltzer tablet when it was dissolved in water. Then, we discussed the significance of the numbers and symbols on the periodic table and did some math to figure out the number of protons, neutrons, and electrons in various atoms and ions. Students also learned the difference between metals, metalloids, and nonmetals and colored their periodic tables to differentiate between each category. All of those concepts paved the way for students to be able to identify bonds as ionic or covalent. After practicing with that, students examined salt (ionic bond) and sugar (covalent bonds), and we discussed the difference in their intermolecular forces after comparing the time it took for the two to melt. Finally, we completed a lab to test the conductivity of different substances (water, sucrose, sodium chloride, and barium chloride). Because conductivity is a property of ionic compounds when dissolved in water, most students found that the solutions of sodium chloride and barium chloride had the greatest conductivity.
Some key takeaways from today include:
- The atomic number represents the number of protons in an element. When the element is in ion form, the number of electrons does not equal the number of protons
- Metals, metalloids, and nonmetals have characteristic properties, especially with electron transferring and sharing. Metals form ionic bonds with nonmetals, whereas two nonmetals form covalent bonds
- Unlike molecules with covalent bonds, compounds with ionic bonds can conduct electricity when dissolved in water
If you would like to ask your child some dinner table questions, you could ask:
- How can you tell what the number of protons, electrons, and neutrons an element has just by looking at the periodic table?
- If you were an element, which one would you be? What are some properties of that element based on what you know about metals, metalloids, and nonmetals?
- What is the key difference between an ionic and covalent bond? How can you tell if a bond is ionic or covalent when given the chemical formula for a molecule?
- Why did the sucrose solution and the water still conduct some electricity even though they were not ionic? What could have been a source of error in that lab?
I am looking forward to day 4 of SAVY, where students will learn about the characteristics of light.
Have a wonderful evening,
Ms. Pao