AACT Resources to Help You Teach Atomic Structure

As chemistry teachers around the country plan activities for their students, AACT will be highlighting resources from our high school library that can help to reinforce topics in different units throughout the school year. We started the year with resources that could be used to support a chemistry basics unit and followed that up with a unit on chemical measurements.

We now move on to lessons, activities, labs, projects, videos, simulations, and animations that can be used to support a unit plan for atomic structure. This plan includes the topics of atomic theory, the mole concept, isotopes and average atomic mass, conservation of mass, electrons and electron configurations, and electromagnetic radiation.

Atomic Theory:

Introduce the development of atomic theory by using one or more of our Founders of Chemistry videos. The Ancient Chemistry Video traces the history of chemistry from the discovery of fire, through the various metal ages, and finally to the great philosophers. Students can learn about Rutherford's initial research on alpha particles in the Ernest Rutherford Video and hear about how he hypothesized that they were helium nuclei. The Niels Bohr Video tells the story of Niels Bohr, a great scientist who redefined how we think about atoms and the electron.

After viewing the videos, use The Scientists Behind the Atom Project to have your students create a digital or paper book about the scientists who contributed to our understanding of the atom. This project will help students explain the specific contributions of several scientists and understand past and current theories regarding the structure of the atom.

Alternatively, you may want to use the Building an Atom Simulation to have your students manipulate the number of protons, neutrons, and electrons in an element and determine how these effect the mass number, atomic number, and other properties of an atom. This lesson, which is guided by a PhET simulation, allows students to see how they can use the number of protons, neutrons, and electrons in an element to predict its identity.

The Mole Concept:

Show your students the Amedeo Avogadro Video from our Founders of Chemistry collection to begin their exploration of the mole concept. This video tells the story of Amedeo Avogadro, the scientist given credit for the mole concept as the result of his study of gases.

Your students can then complete the It’s Mole Time lab to learn how to calculate the molar mass of a substance, the number of moles of a compound in a given mass, and the number of molecules of a compound in a given mass. During the lab, students determine the number of moles of chalk used to write their name, the moles of sucrose ingested while chewing gum, and the moles of alcohol evaporated when using hand sanitizer.

If your students need a bit more practice, have them use the Calculating Moles lab to help them understand the mole concept and convert mass data into values of moles, atoms, or molecules. Students can work individually or with a partner to practice using dimensional analysis to solve mole conversion problems.

Isotopes and Average Atomic Mass:

Students can learn how the average atomic mass is determined through a tutorial based on the isotope abundance for Carbon with our Isotopes & Calculating Average Atomic Mass simulation. They then select the number of isotopes, the mass of each isotope, as well as the abundance of each to successfully build a mystery element and calculate its average atomic mass.

If you would prefer a hands-on activity, our Beanium Isotopes lab will lead your students through the steps that they will take to calculate the average atomic mass of an imaginary element called Beanium.

Conservation of Mass:

Introduce the concepts of conservation of mass and the law of definite proportion with our Founders of Chemistry video. This video tells the story of how Antoine Lavoisier, who many consider to be the father of modern chemistry, discovered oxygen and hydrogen and first proposed the Law of Conservation of Mass.

Following the video, have your students use the Balancing Legos activity to model the reactants and products in a chemical reaction. They use these “atoms” and “molecules” to balance the chemical reaction to demonstrate the law of conservation of matter. The Chemistry in a Bag activity is also available to use as a demonstration or lab to have your students make observations about the Law of Conservation of Mass.

Electrons, Electron Configurations, and Electromagnetic Radiation:

With the use of the Bohr model to introduce atomic structure, students visualize electrons “orbiting” around the nucleus. Help them expand their knowledge with our Orbitals Animation, which allows students to visualize how orbitals are superimposed upon one another within an atom in three dimensions. The orbitals depicted in this animation are 1s, 2s, 2p, 3s, 3p, 4s, and 3d.

You can then use the Exciting Electrons Simulation from the March 2015 issue of Chemistry Solutions to let your students explore what happens when electrons within a generic atom are excited from their ground state. They will see that when an electron returns to its ground state from an excited state, energy is released in the form of electromagnetic radiation.

Finish up your study of electrons with our Flame Test: Going Further lab which allows students to investigate the colors produced when several mixtures of metallic ions are placed in a flame. Note that this updated procedure uses wooden splints and aqueous solutions in place of the traditional flammable solvent. Read more about this in the ACS Safety Alert about the Rainbow Demonstration.

We hope that these activities will help you reinforce several of the topics covered in a unit on atomic structure. Most of these lessons were made possible by great teachers sharing their own resources. We need your help to keep the collection growing.

Do you have a great demonstration, activity, or lesson about any topics relating to Atomic Structure that you would like to share with the community? Please send it along for consideration.