Quantum Concepts in Chemistry ( 1 Prerequisites for Acquisition of Quantum Concepts and Their Comprehension by Undergraduate Chemistry Students

Quantum Concepts in Chemistry ( 2 The Boston University Team Peter Garik (presenting) Luciana Garbayo School of Education Alan Crosby, Dan Dill, Alexander Golger, and Morton Z. Hoffman Department of Chemistry Peter Carr Science and Mathematics Education Center

Quantum Concepts in Chemistry ( 3 Exploring Quantum Concepts in Chemistry This project is funded by the U.S Department of Education’s Fund for the Improvement of Post Secondary Education (FIPSE).

Quantum Concepts in Chemistry ( 4 Project Objectives The objectives of our FIPSE project are to find ways to introduce quantum concepts into the chemistry curriculum; to design software that will support the teaching of quantum concepts; and, to evaluate the success of our software and curricular activities in supporting student learning of quantum concepts.

Quantum Concepts in Chemistry ( 5 Why Quantum Concepts? Why teach quantum concepts at an early stage in the chemistry curriculum? The epistemology of a mature science relies upon foundational models for its research program. Such models provide a unifying perspective on the physical world and support the best insights and reasoning that we can currently achieve.

Quantum Concepts in Chemistry ( 6 Why Quantum Concepts? For cosmology, it is the inflationary theory of the universe. For geology, it is plate tectonics. For biology, it is Darwinian evolution.

Quantum Concepts in Chemistry ( 7 Why Quantum Concepts? For chemistry, one of the foundational models is unarguably the quantum theory of atomic structure and electronic behavior. The pedagogical issue is where does it belong in the curriculum? Quantum concepts appear burdened with additional abstractions (including mathematics) that make them first appear forbidding to teach.

Quantum Concepts in Chemistry ( 8 Why Quantum Concepts? We argue that the unifying power of quantum concepts is so great, and their utilization for modern chemistry so extensive, that finding ways to successfully introduce them at an early point in chemistry education is our obligation to the students.

Quantum Concepts in Chemistry ( 9 Quantum Concepts in Chemistry What are quantum concepts in chemistry? The principal quantum topics in chemistry are: 1) The description of electrons and how they behave in the presence of other charges. (This includes atomic and molecular structure.) 2) The description of the interaction of radiation with matter, and primarily with electrons.

Quantum Concepts in Chemistry ( 10 Quantum Concepts in Chemistry Historically quantum concepts grew out of analogies to electromagnetic theory. Since the interaction of radiation with matter is a key concept in chemistry (spectroscopy), it is traditionally taught. The properties of electromagnetic waves provide an early access point for what we refer to as “Quantum Readiness.”

Quantum Concepts in Chemistry ( 11 Elements of Quantum Readiness Quantum readiness includes understanding: What a wave is: time and space dependence What an electromagnetic wave is: –associated electric field –associated magnetic field The relationship between amplitude and intensity Constructive and destructive interference

Quantum Concepts in Chemistry ( 12 Elements of Quantum Readiness How charged particles interact How a light wave interacts with a charged particle What a quantum of energy is Students prepared with these concepts should have analogies for understanding quantum phenomena.

Quantum Concepts in Chemistry ( 13 Quantum Concepts for Chemistry What are the quantum concepts that we would like students to master? The delocalization of the electron and its description by a probability amplitude. The quantization of energy levels. The pairing of a wave function with an energy. Constructive and destructive interference. The Pauli Exclusion Principle.

Quantum Concepts in Chemistry ( 14 Quantum Concepts in Chemistry The transition in energy levels associated with absorption and emission of radiation. The geometry of atomic and molecular orbitals. The atomic structure that arises from the Aufbau Principle.

Quantum Concepts in Chemistry ( 15 Evaluating Students’ Conceptual Understanding of Quantum Concepts As a first step to determining how students learn quantum concepts, we engaged in a qualitative research project.

Quantum Concepts in Chemistry ( 16 Theoretical Background and Methodology Chi and Slotta (1993) categorized entities as matter (objects), processes, and mental states. For example, if a student thinks that a photon is an “object”, then with it comes a host of associations such as the photon energy object collides with an electron and knocks it to another orbital.

Quantum Concepts in Chemistry ( 17 Theoretical Background and Methodology We add to these categories the field category in order to have a sensible set of categories for quantum entities.

Quantum Concepts in Chemistry ( 18 Design and Procedures 1)We interviewed students prior to, and subsequent to, instruction on quantum concepts. 2)Students were selected from a pool of volunteers taking the honors general chemistry course at a research university.

Quantum Concepts in Chemistry ( 19 Discussion The students exhibited a series of misconceptions, many of which match those reported in the physics education literature. Here we focus on students’ difficulty in understanding the field nature of the electromagnetic field and the field nature of orbitals.

Quantum Concepts in Chemistry ( 20 Pedagogical Strategy We have designed software to provide students with bridging analogies to understand the properties of waves and fields. The software modules have been authored in Pedagogica™ as described in earlier talks. Over the course of the next year we will be testing the effectiveness of this software to assist students in understanding the nature of electronic orbitals and atomic structure. (Go to Waves Module!)