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Sunday, September 13, 2015

The One Where We Compare Dog Sitters & Nuclei

Unit 1.A: Atomic Structure 

"Don't trust atoms, they make up everything."

Practice Problems:

  Problems that revolved around simple vertical and horizontal relationships were easier to understand in comparison to problems that compared a neutral atom and an ion in terms of ionization energy.
Ex. of Understood Problems

"Which element has a larger ionization energy, lithium or beryllium?" 
Beryllium (located on the right of lithium on the periodic table)

These problems concerned horizontal relationships and compared how many protons were included in a neutral atom of a certain element. Generally, elements with more protons had a larger ionization energy and a smaller atomic radius. This was because the more protons located in the nucleus of an atom (assuming the atoms being compared have the same amount of energy levels), the stronger the attraction between the charged particles.

"Which element has a larger atomic radius, oxygen or sulfur?"
Sulfur (located under oxygen on the periodic table)

These problems had to do with vertical relationships and compared elements that had different amounts of energy levels shielding its protons. With these problems, elements with less energy levels had a larger ionization energy and a smaller atomic radius. Because the distance between the charged particles (protons and electrons) was smaller in elements with less energy levels, these elements had larger ionization energy levels and a smaller atomic radius.
Ex. of Challenging Problems

"Do you predict the atomic radius of the sodium atom, Na or ion, Na+ to be larger? Explain."
Na (smaller ionization energy)

Problems like this one compared the ionization of an element's neutral atoms and ions. This was a little tricky for me because at first I made the common mistake of thinking that positively charged ions had added protons rather than less electrons. After learning that ions were created after only either adding or losing electrons, I was able to figure out that positive ions had a larger ionization energy and that negative ions had a weaker ionization energy in comparison to neutral atoms.

Day 2: We learned about the chemicals inside cigarettes, color-coded our periodic tables and discussed the structure of atoms.

Day 3: We conducted an experiment in which we were able to burn copper, sodium, lithium, potassium, and beryllium with Bunsen burners. After, we discovered that each element gave off a different color when burned.


Day 4: We came up with models that summarized what we learned from the flame test experiment from day 3. Next, we used magnets and cardboard to model how ionization energy can change.

     Just as with the practice problems, the quiz problems that involved horizontal and vertical relationships were the ones that I understood and had an easier time answering. What did confuse me was the questions that asked about atomic radius instead of ionization energy. Since I was expecting problems that were only about ionization energy, I almost did not realize this and nearly got several incorrect.

  • Where else can I apply Coulomb's Law?