Skip to Content

Systems and Scale | Goals

Systems and Scale Unit General Information

The goal of the Systems and Scale unit is to introduce students to organic matter and chemical energy (in the context of combustion) using the tools for reasoning and environmental literacy practices that students will engage with in other units. Students must be able to identify organic matter from inorganic matter, and understand how differences in the chemical make-up of materials influences how materials and energy are transformed and moved between systems.

Unit Goals

The tables below show goals for this unit in two forms. Table 1 shows unit learning objectives aligned with inquiry and application practices. Table 1 also contrasts the goal performance with performances of students at lower learning progression levels.

This table is followed by a list of Next Generation Science Standards (NGSS) addressed by this unit.

Table 1: Unit Learning Objectives


Type of Objective and   NGSS Practices

Learning Objective Challenges for Level 2 Students Challenges for Level 3 Students
Inquiry: Measurement
 
3. Planning and carrying out investigations
 
4. Analyzing and interpreting data
 
5. Using mathematics and computational thinking
 
8. Obtaining, evaluating, and communicating information
Measure mass changes in materials undergoing chemical change.
 
 
 
Detect changes in carbon dioxide concentration in air samples.
Level 2 students may have trouble reading digital balances and attaching meaning to measurements in small fractions of grams.
 
Level 2 students will not think of air as a mixture of different gases, so while they can understand that BTB detects CO2, they will not think of CO2 as one of the mix of gases in the air.
Level 3 students may have trouble accounting for tare mass and interpreting small fluctuations in readings on digital balances.  They will have difficulty identifying threats to accuracy and precision in measurement.
 
Inquiry: Arguments from evidence
 
2. Developing and using models
 
4. Analyzing and interpreting data
 
5. Using mathematics and computational thinking
 
6. Constructing explanations
 
7. Engaging in argument from evidence
 
8. Obtaining, evaluating, and communicating information
Use evidence about changes in mass of fuels and carbon dioxide concentration to defend claims about movements of atoms during chemical changes. Level 2 students will not interpret changes in mass as evidence of movements of atoms, believing instead that fuel is “burned up.”  They will also believe that oxygen can be converted to CO2—they will not be committed to the idea that the carbon must have come from somewhere. Level 3 students will see the relevance of evidence to claims, but they will not systematically consider alternate hypotheses or show how evidence supports or refutes specific claims.
 
Inquiry: Collective validation
 
3. Planning and carrying out investigations
 
4. Analyzing and interpreting data
 
5. Using mathematics and computational thinking
 
7. Engaging in argument from evidence
 
8. Obtaining, evaluating, and communicating information
Find patterns in data collected by multiple groups about changes in mass and carbon dioxide concentration. Level 2 students may focus primarily on their own results rather than seeing the value of multiple measurements. Level 3 students will understand that multiple measurements are valuable, but they will have few strategies for finding patterns across multiple trials.
 
Application: Movement question
 
2. Developing and using models
 
4. Analyzing and interpreting data
 
6. Constructing explanations
 
7. Engaging in argument from evidence
 
8. Obtaining, evaluating, and communicating information
 
Describe systems and processes in a hierarchy of scales, including atomic-molecular, macroscopic, and large scale.
 
 
 
Draw and explain movements of materials during a chemical change.
Level 2 students will explain what happens as an action of the flame (the flame burns up fuel).  They will not interpret mass loss in the fuel as evidence that atoms are moving.
Level 3 students will describe a general upward movement of materials in the flame, but may not include all relevant materials (fuel, oxygen, CO2, water vapor) in their accounts.
 
Application: Carbon question
 
2. Developing and using models
 
5. Using mathematics and computational thinking
 
6. Constructing explanations
 
7. Engaging in argument from evidence
 
8. Obtaining, evaluating, and communicating information
 
Classify materials as organic or inorganic based on observable characteristics (organic materials include foods, fuels, and tissues of organisms) or molecular bonds (organic materials have C-C and/or C-H bonds).
 
 
 
Explain chemical changes as atoms being rearranged into new molecules.
Level 2 students will explain what happens as an action of the flame (the flame burns up fuel) rather than as a chemical change in which atoms and mass are conserved.   They will recognize that flames need and use fuels and oxygen, but they will not try to trace those materials through the chemical change process.
Level 3 students will recognize that a chemical change is taking place, but they will not be able to successfully trace all the materials through the flame.  They may say that the fuel is converted to energy.
 
Application: Energy question
 
2. Developing and using models
 
4. Analyzing and interpreting data
 
5. Using mathematics and computational thinking
 
6. Constructing explanations
 
7. Engaging in argument from evidence
 
8. Obtaining, evaluating, and communicating information
Identify forms of energy involved in combustion (chemical energy, light, (motion), heat energy) and distinguish them from forms of matter (e.g., fuels) and phenomena (e.g., flames).
 
 
 
Explain energy transformations during combustion: Chemical energy stored in C-C and C-H bonds of fuel molecules is transformed into heat and light.
Level 2 students will recognize heat and light are forms of energy in the flame, but they will not be committed to the idea that the energy must have a source.  (The flame could create energy.) Level 3 students are likely to identify the fuel as an energy source for the flame, but they may not distinguish between fuel as a material and chemical energy within the fuel.