Modifying the Curriculum in General Chemistry

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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
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Traditional Approach to General Chemistry vs.
Atoms First

• TRADITIONAL
• 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

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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.

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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

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Exam Analysis

• Compare Final Exam Results
• 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

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Assessing this approachQualitatively

• 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

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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 72
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Thermodynamics
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Aqueous
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Test Progression Colligative Properties
Atoms first Approach
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Test ProgressionIntermolecular forces
Intermolecular forces and properties of
liquids 2004 3 questions on Final exam 2005
10 questions on 3 exams
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Survey results

• Survey Questions 3 in each area
• Sequence of topics
• Difficulty of material in relationship to
  sequence
• Role of textbook in determining sequence
• Scale
• Strongly agree
• Agree
• Neither
• Disagree
• Strongly disagree

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Sequence of Topics
Knowledge of atomic structure helped with
conceptual understanding of material.
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Difficulty of material in relationship to
sequence
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Role of Textbook in determining sequence
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Summary survey

• Sequence of Topics
• 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)

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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.

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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!

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Unforeseen Consequences

• Mismatch between lecture and lab
• Lab focuses on reactions
• Students encounter material in lab before it is
  covered in lecture

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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

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Atomic structure