This lesson will introduce students to a visual model of atomic structure and the reactivity of certain atoms due to their atomic structure. Students will examine various models of atomic structure and observe patterns in electron configuration that differ between reactive and nonreactive elements. Algorithms used to determine the subatomic structure of an element based on its atomic mass and atomic number will be practiced individually and then in small groups. This activity will allow them to understand how an elements react constantly in our physical world (often leading to chaos) whole trying to maintain a balance (homeostasis) in all systems including the human body.
Physical Science: An element is composed of a single type of atom. When elements are listed in order according to the number of protons (called the atomic number), repeating patterns of physical and chemical properties identify families of elements with similar properties. This "Periodic Table" is a consequence of the repeating pattern of outermost electrons and their permitted energies.
Atoms interact with one another by transferring or sharing electrons that are furthest from the nucleus. These outer electrons govern the chemical properties of the element.<
Knowledge of basic subatomic particles that make up atoms; General knowledge of the patterns of the periodic table.
a. Time frame: 90 minutes
b. Materials: Bohr model examples, 3-D molecular building kits
c. Resources: Chemistry Textbooks
-Teacher Instruction: The teacher introduces the Bohr model (or a similar model), how it represents the protons/neutrons in the nucleus, and how the electrons are arranged in shells.
-Student Activity 1: Students work individually and study Bohr models of various atoms, ranging from very reactive to inert. They try to find patterns among the atoms that correspond with their degree of reactivity. They record their ideas of patterns and reactivity in their learning logs. (See the following world wide web site for learning logs samples; http://www.sdcoe.k12.ca.us/score/actbank/tjournal.htm)
-Student Activity 2: Students will then be given a set of elements represented by the bohr model to observe and determine reactivity. They will sequence them from most reactive to non-reactive by observation alone. They will then explain reasons for their sequenced elements.
-Student Activity 3: In small groups, students are assigned several atoms which represent highly reactive elements to non-reactive elements. Students produce Bohr models of each, as well as, producing 3-D models of each atom by using the molecular building kits. Each group will then "check" each others work by moving from station to station and determining the "proper" atomic configuration for those assigned elements.
-Student Activity 4: In those same small groups, students will access NIH imaging of specific elements and compounds. (see site here) Students will draw and label those images along with explanation of each elements reactivity.
Learning logs could be graded for understanding and misconceptions. Individual reactivity sequences could be handed in and graded. Student groups will grade each others models by completing a group assessment sheet; (ie. Group Names.... Group Elements.... Proper Electron Configuration... Proper Modeling...Reactivity Assessment, etc.) Teachers can do a check off list by moving around the room from group to group while assessing their work. Participation points could be given here, as well. NIH imaging drawings and labels should be turned into the teacher. Students could take a short quiz over several elements and their proper atomic structure in regards to protons, neutrons, and electrons, and the reactivity of each the following class period.
World Wide Web site for learning logs samples; http://www.sdcoe.k12.ca.us/score/actbank/tjournal.htm). NIH imaging access.