Chemistry Mini-Lesson: "Model of an Atom"

Dr. Richards 10th grade Chemistry Standard Ie (“Atomic & Molecular Structure”): Students know the nucleus of the atom is much smaller than the atom yet contains most of its mass. Topic (textbook pages, lesson number, unit). Time allotment: 1 class period (50 minutes)

Materials Needed:

Materials for building atoms: pipe cleaners, cotton balls, colored markers, crayons, construction paper, wire, coat hangers, or other creative materials (common household items) Handout including directions for building the model with rubric on back.

Objectives:

After presenting information on the structure of an atom and the development of the model of an atom, students will be able to create a model of an atom that includes the protons and neutrons in the nucleus and the electrons.

Procedures:

Introduction: Begin with a class discussion about atoms. What do they already know about atoms? Include some interesting facts: "Did you know?... If an atom were the size of a football stadium, the nucleus would be so small, it would be a penny on the 50 yard line." "Did you know? If you tried to lift the penny-sized nucleus of your football-sized atom, it would weigh several hundred tons (or as much as the entire football field)." Use a short clip on “You Tube” called, “A is for Atom”. Have students fill out a worksheet about the video to check for understanding. Students should know that atoms are the smallest unit of matter. They make up everything. Atoms cannot be created or destroyed (but they can be changed i.e. chemical reactions). Atoms have a very dense nucleus, composed of positively charged protons and neutrally charged neutrons. Most of the atom is empty space surrounding the nucleus where the negatively charged electrons zip around in orbits. Instruction: Explain to students that they will be creating their own model of an atom in small groups. They can use any material they desire to construct their atom. Pass out the handout with the directions and rubric. The atom must contain a nucleus with protons and neutrons and electrons orbiting around the nucleus. After they’re done making their models, they will present their models to the class (5 minutes each). Closing: Students will present their models to the class and explain how they came up with their model (5 minutes each).

Assessment

• Pre-assessment: answering the worksheet in response to “A is for Atom” video and subsequent discussion.
• Formative assessment: construction of the atomic model using the rubric and short presentation to the class.
• Informal assessment: I will circulate as students construct their atomic models to make sure they are on the right track.