2. Electrons
electron configuration
Electron configuration: We began Journey 2, Phase 1, of Honors Chemistry class by learning about Electron Configurations. Electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals. It is the method of writing the location of electrons in the atom. The level and sublevel is written followed by the subscript with the number of electrons.
Magnetism: During the next portion of the class, we performed a lab using magnets. Magnetism is an event that occurs where there is the motion of electric charges, resulting in attractive and repulsive forces between objects.
Iron: [Ar] 3d6 4s2
Magnetism: The goal of this lab was to develop and conduct an experiment to test differences in magnetism between samples of iron and zinc using a magnet. The materials we used were Zinc and Iron samples, a petri dish, ruler, and a magnet. In this experiment, we took samples of Zinc and Iron individually, placed in a dish, placed a magnet under each, and observed if metal was attracted to the magnet and at what distance from the magnet did the metal display that there was attraction. From our observation, we found that Zinc was not affected at all by the magnet and Iron showed attraction at a distance of 1 cm from the magnet. We concluded that Iron is magnetic and Zinc is not.
Zinc: [Ar] 3d10 4s2
The reason for this result can be determined by studying the electron configurations. Iron was more attracted to the magnet because it was missing more of its outermost electrons. Iron was trying to take electrons from the magnet, making it more attracted to it. Therefore more electrons can be added to make it more conductive. No electrons can be added to Zinc.
Orbital / Subshells: Electrons are found in areas called shells. A shell is also called an energy level. Shells are areas that surround the center of an atom named K, L, M... Shells are described by the regions in which they are found. "K" shell is closest to the nucleus, and "Q" is farthest away from it. For simple atoms, the "n" values are the energy levels and match the row number on the periodic table. Next, electrons are described by how they act inside their shells. These are described with the "l" value. The "l" values tells what suborbital an electron is found in. These are s, p, d, f, g, and h.
Photoelectron Spectroscopy
Photoelectron Spectroscopy (PES): During this portion of the class, we learned about photoelectron spectroscopy. PES is a technique used to determine the identity of an atom or molecule by measuring how difficult it is to eject all of its electrons. The machine scans a substance and determines the number of electrons surrounding the nucleus. (The amount of electrons is unique for each element.) The instrument produces a graph similar to the one shown here.
Homopolar Motor: A Homopolar Motor is a type of electric motor that uses direct current to power a rotational movement that is generated by a battery. Two magnetic poles are provided by the single permanent magnet that is used to produce the magnetic field and to generate a rotational movement.
Homopolar Motor: The goal of this lab was to create a homopolar motor. The materials we used were a battery, a magnet, and a pair of wire cutters. In this experiment, we took a battery and placed it on top of a magnet, shaped the wire into what looked like a heart, placed the bottom of the heart-shaped wire on the magnet end of the apparatus to touch the bottom of the magnet, and placed the inward shaped portion of the wire so that it contacted the top of the battery. We hen observed. From our observation, we found that the wire begin to spin around the battery. We concluded that we created a circuit that caused the wire to have a strong magnetic field around the battery.
Binding Energy
Binding Energy: In this final portion of Journey 2, we learned about Binding Energy. It is the energy required to remove the outer most electron from any element. Note that moving horizontally across a row, from left to right on the Periodic Table, the Binding Energy increases due to the increase in the number of protons on a given energy level. Moving vertically down a column on the Periodic Table, the Binding Energy decreases due to more energy levels are shielding the outermost electrons from the pull of the nucleus.
Binding Energy: The goal of this lab was to design and conduct an experiment to determine the relationship between Energy Levels and Binding Energy and Protons and Binding Energy. The materials we used were pieces of cardboard, different size magnets, and a rubber band with a magnet attached to it. (The cardboard pieces represented the different energy levels. The different size magnets represented protons. The magnet attached to the rubber band represented electrons. And the the rubber band attached to the magnet represented the amount of Binding Energy it took to pull the electron away.) In this experiment, we set up the magnet (electron) on top of the cardboard , pulled the rubberband until it released, and measured when the electrons were released. From our observation, we found that the more energy levels (cardboard) we added, the easier it was to remove the electron (rubberband/magnet). We concluded that the Binding Energy increases because the number of protons attracting electrons for any given energy level increases, so the more energy levels, the higher the binding energy.
reflection
I learned so much from Journey 2 of Honors Chemistry. I really enjoyed the lab experiments and learning all of the material. These were such interesting concepts and I felt that I understood them for the most part. Ramsey is such an amazing teacher, and I am loving the class. As the final phase of our class concluded, I prepared for the test. I did this by reviewing class notes, my labs, and the homework. I felt that I was prepared for the test, but because I was a little overwhelmed with so many exams that week, I missed a question on the test.
Overall, I learned a lot of information and I love everything about the class so far.