This past year, my school was transitioning to a new 4-year curriculum. To help get it started, I taught 2 sections of the new first year course: Modeling Chemistry. It was the first time the class was happening, my first (and probably last) time teaching chemistry, and there weren’t a lot of other 9th grade chemistry models to use. We aimed to do the first 8 units, and we did the first 7. (My getting put on a jury in the spring, among other things, slowed us down a little bit.)

We used standards-based grading for the class. It was a version of my 5, 6, 8, 10 style where I used the average of the top 3 scores for each skill rather than the maximum. (I will use something similar, with a little tweaking for next year in the 10th grade physics class, too. Blog post to come, probably.)

I didn’t do this on my own

I (very luckily) had a lot of help with this course and with writing these objectives. You will notice that I relied heavily on work from Lauren Stewart (check out her entire blog while you are at it—her series of ModChem posts are linked to her 180 blog posts about each individual day, and they were an invaluable resource as I thought through each unit this year). I was really, really fortunate to have my awesome, flexible, and thoughtful colleague Alan Kim teaching the other 2 sections and collaborating with me all year. I got at least weekly (virtual, remote) support from the wonderful Kara Luce all year who had no reason to give me so much of her time to help make sure I understood what I was doing with the chemistry. And I had great support with teaching and with implementing and adjusting my grading system all year from the academic dean at my school, Allison Isbell, and from my math colleagues who were also using SBG in their Math 1 classes (half the 9th grade).

Student reflections

At the end of the year, I asked students (among many other questions), “Consider the grading system in this class. What do you like about it? Dislike about it? Has it had any impact on your learning or experience?” Here are a few of their reflections.

• I really like the way we are graded because there is actual opportunity for improvement and a mistake doesn’t permanently lower our grade. I think it has provided more incentive to retake quizzes and go back to a skill because only the best scores are part of our grade and makes Chemistry NOT STRESSFUL!
• I find the short quizzes very helpful. It takes the stress away, and the taboo of taking retake quizzes. The grading using the short quizzes makes so much sense, for it is NOT about when you understand it/if you are the first to understand it, but if you understand it. For someone who it takes longer to proccess things, it makes life so much more easier (I wish they did this in math too)!
• I like how we can see the exact skills we are struggling with so that we can focus on that skill and improve it.
• I really like the grading system because it is about how much you try in class. For example in the beginning of the year I didn’t really understand anything at first but I still did well because I was trying and I eventually understood.
• I think the grading system is great at evaluating progress and I think it is one of the most fair systems I have ever come across.
• I love the grading system. It motivates me to keep trying, because the grades are maliable, and I think it should be the basis for all the grading systems at LREI.

Course Description

Scientific Abilities

Unit 01: Physical Properties of Matter

• Draw particle diagrams that include features of mass, volume, and density
• Represent substances and changes in substances at the particle level that are consistent with the Law of Conservation of Mass

• Experimentally, graphically, and mathematically determine the mass, volume, and density of a substance
• Use units in all work (and not only in answers!)

Unit 02: Particles in Motion

• Relate temperature to the thermal energy of particles in motion
• Describe the characteristics of solids, liquids and gases in terms of particles and their arrangement
• Use particle diagrams to account for motion and density differences; describe the process of how the arrangement of particles changes during phase changes.

• Draw diagrams to represent changes in gases as these quantities change
• Explain the basic tenets of Kinetic Molecular Theory and use it to explain changes in gases

Unit 03: Energy Storage and Transfer

• Show energy stored in appropriate flavors (thermal, phase, chemical) before and after a transfer occurs.
• Identify and name the system and the surroundings.

• Distinguish between phase changes and temperature changes.
• Draw particle diagrams that match different sections of a graph.
• Use words to explain the meaning of each part of a graph.

Unit 04: Describing Substances

• Use particle diagrams to show the differences between these substances.
• Distinguish between pure substances and mixtures.
• Identify and describe the differences in physical properties between mixtures and pure substances.

• Use words to describe how and why your procedure will work.
• Actually do procedures in the classroom to separate mixtures.

• Use Avogadro’s Hypothesis and combining volumes of gases to deduce the composition of some compounds.
• Use data from experiments to determine volume and mass ratios when gases combine.
• Use particle diagrams and the laws of definite and multiple proportions to determine the composition of gases.
• Calculate the percent composition of compounds using data about masses.

Unit 05: Counting Particles

• Use information from the periodic table to connect the mass and number of moles for an element.
• Use information from the periodic table to figure out the molar mass of a compound.
• I can calculate the molar mass of a given chemical formula of a substance.

• Use Avogadro’s Number to determine the number of particles (atoms or molecules) in a substance when you know the number of moles of the substance.

• I can determine the relative mass of molecules by using experimental data and applying Avogadro’s hypothesis.
• Use words and diagrams to describe and show the differences between empirical and molecular formulas.

Unit 06: Particles with Internal Structure

• Describe the unique properties of each.
• Explain and represent how ions are formed from atoms.
• Talk about macroscopic and microscopic behavior.

• Describe the unique properties of each.
• Talk about macroscopic and microscopic behavior.

• Determine whether a substance is ionic or molecular from the name or formula of a substance

Unit 07: Representing Chemical Change

• Draw appropriate and accurate bar charts (LOLs) that show how the energy is stored and transferred.
• Explain energy ideas in words and construct arguments that use diagrams as evidence.
• Distinguish, in terms of energy, between phase and temperature changes.
• Make calculations using the bar chart as a starting point.
• Keep units attached to all work, not only answers.

• Represent the role of chemical energy and thermal energy in a chemical reaction.
• Describe endothermic and exothermic reactions in terms of storage or release of chemical energy.

• Explain and make use of how the coefficients in a chemical equation describe the quantities of substances involved
• Explain and make use of how the subscripts describe the number of atoms involved

• Demonstrate conservation of mass and atoms through a balanced chemical equation
• Use particle diagrams to show how an equation is balanced
• Balance an equation for a reaction

• Identify patterns in the way substances react
• Use patterns to predict what products result when substances react