Modifying the Curriculum in General Chemistry An assessment of the Atoms-First Approach Mary J. Bojan Ruth Bowers Ralph Locklin The Pennsylvania State University Department of Chemistry

Traditional Approach to General Chemistry vs. Atoms First Nomenclature Stoichiometry Aqueous reactions Energy (Enthalpy) in reactions Structure/properties of atoms Structure/properties of molecules Properties of gases, liquids , solids Properties of aqueous solutions Kinetics Equilibrium ATOMS FIRST Structure/properties of atoms Nomenclature Structure/properties of molecules Properties of gases, liquids , solids Properties of aqueous solutions Stoichiometry Aqueous reactions Energy (Enthalpy) in reactions Kinetics Equilibrium Cannot control how topics line up with calendar 11/16/2018 Mary J. Bojan 19th BCCE

Rationale: build from the basics Start with basics: Structure/properties of atoms Structure and properties of molecules Emphasize: structure effects function Interaction of energy with matter incorporated throughout Photon interacting with matter Electrostatic forces Intermolecular forces Bond energies Reactions introduced AFTER structure and properties are understood Finally: thermodynamics (equilibrium) and kinetics can be understood. 11/16/2018 Mary J. Bojan 19th BCCE

Assessment Compare results from two similar classes Fall 2004 (traditional sequence) Fall 2005 (atoms first sequence) 4 of 5 instructors are the same Deliver Content Write exams Overall content for both courses was same (no material was added or deleted) Exams given in evening at same time of day Format of exams (MC) and # of questions per exam is same Student Demographics are the same 11/16/2018 Mary J. Bojan 19th BCCE

Exam Analysis Compare Final Exam Results Marker Questions Fall 2004 (traditional sequence) Fall 2005 (atoms first sequence) Comprehensive Final 72% mean for both semesters Marker Questions Similar questions from exams encountered at different times in the semester Test Progression Same concepts encountered in later exams during the same semester. Topic Groupings Total number of exam questions in a broader topic area 11/16/2018 Mary J. Bojan 19th BCCE

Assessing this approach Qualitatively Survey of students 194 students responded to survey 72% were first semester freshman 5% (10 students) had taken course with “old” sequence Survey Questions Sequence of topics Difficulty of material in relationship to sequence Role of textbook in determining sequence 11/16/2018 Mary J. Bojan 19th BCCE

Marker Questions Topic 2004 2005 Equilibrium Final 80% Final 79% Net Ionic Equations Final 64% Final 73% Gas Laws Exam 3 81% Exam 2 80% Atom/ion Structure Exam 1 88% Exam 1 95% Bohr Model Exam 2 76% Exam 1 68% Quantum Numbers Exam 2 77% Exam 1 78% Final Exam 72% 11/16/2018 Mary J. Bojan 19th BCCE

Thermodynamics 11/16/2018 Mary J. Bojan 19th BCCE Same number of questions spread out over 2 exams. Ultimately, results are very much the same. In 2004, material all covered before first exam. Typically in traditional unit this material was split and not learned as well by students. In FA 2005, material is split up by Thanksgiving week. 11/16/2018 Mary J. Bojan 19th BCCE

Aqueous 11/16/2018 Mary J. Bojan 19th BCCE

Test Progression Colligative Properties Atoms first Approach 11/16/2018 Mary J. Bojan 19th BCCE

Test Progression Intermolecular forces Intermolecular forces and properties of liquids 2004: 3 questions on Final exam 2005: 10 questions on 3 exams 11/16/2018 Mary J. Bojan 19th BCCE

Survey results Survey Questions 3 in each area Scale Sequence of topics Difficulty of material in relationship to sequence Role of textbook in determining sequence Scale Strongly agree Agree Neither Disagree Strongly disagree 11/16/2018 Mary J. Bojan 19th BCCE

Sequence of Topics Knowledge of atomic structure helped with conceptual understanding of material. 11/16/2018 Mary J. Bojan 19th BCCE

Difficulty of material in relationship to sequence 11/16/2018 Mary J. Bojan 19th BCCE

Role of Textbook in determining sequence 11/16/2018 Mary J. Bojan 19th BCCE

Summary: survey Sequence of Topics Difficulty of material 65% agree/strongly agree that topic sequence is logical (only 19% disagree) 62% agree/strongly agree that knowledge of atomic structure helped with conceptual understanding (only 15% disagree) Sequence was very different: 39% agree, 29% disagree, 32% neither Difficulty of material Only 26% agreed that the atoms first sequence required extra help early. (49% disagree, 25% neither) 56% agreed that material was easier to understand since reactions came up later. Only 20% disagree. Only 23% agreed that the concepts were more difficult because the sequence was different form the text book (59% disagreed) 11/16/2018 Mary J. Bojan 19th BCCE

Summary: Survey Role of Textbook in determining sequence 32% claimed they had difficulty reading text because it had not been covered in lecture. 59% felt it was important for the textbook to match the lecture (23% disagreed with this) 40% agreed that the atoms first sequence made more sense than the textbook sequence. Another 39% were neutral. 11/16/2018 Mary J. Bojan 19th BCCE

Interview and survey Found the sequence to be logical Did not notice difference between atoms first and their previous courses Did not mind covering material in different sequence from text: syllabus provided a sufficient guide Conclusion: the new sequence did not drastically improve student perception of learning and understanding, but it did not hurt! 11/16/2018 Mary J. Bojan 19th BCCE

Unforeseen Consequences Mismatch between lecture and lab Lab focuses on reactions Students encounter material in lab before it is covered in lecture 11/16/2018 Mary J. Bojan 19th BCCE

Conclusions Faculty perspective: atoms first approach is more logical approach Student performance was not improved but it was not hurt Detailed syllabus was effective guide when material was covered in different sequence from text. Problem: integration of Lab and lecture 11/16/2018 Mary J. Bojan 19th BCCE

Atomic structure 11/16/2018 Mary J. Bojan 19th BCCE