Practice Activity, part 1 Plan an investigation to examine the relationship between the amount of gas and its volume. Identify the materials and write a procedure, identifying the constants and variables. Conduct the investigation and record your observations. Use the rubric to evaluate your work. Gases Portfolio Rubric Practice Activity, part 1 Plan an investigation to examine the relationship between the amount of gas and its volume. Identify the materials and write a procedure, identifying the constants and variables. Conduct the investigation and record your observations. Use the rubric to evaluate your work. Gases Portfolio Rubric