HS-PS1-9

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Analyze data to support the claim that the combined gas law describes the relationships among volume, pressure, and temperature for a sample of an ideal gas.

Clarification statement: Real gases may be included at conditions near STP. The relationships of the variables in the combined gas law may be described both qualitatively and quantitatively.

Assessment boundary: Assessment is limited to the relationships among the variables of the combined gas law, not the gas law names, i.e. Boyle’s Law.

Note: this is a NYSED-specific performance expectation that is different from the Next Generation Science Standards.

Reference Tables

Relevant reference tables:

• Mathematical and Computational Models – combined gas law
• Mathematical Relationships – K = °C + 273.15, 1 atm = 101.3 kPa and STP
• Selected Units
• Selected Metric Prefixes

Regents Exam Questions

Released New York State Regents exam questions that assess HS-PS1-9 are listed here by exam and question cluster. Each link opens the question with its answer key.

Exam	Cluster	Question
August 2026 Chemistry Regents	Parade of Balloons	Question 41
	Parade of Balloons	Question 42
June 2026 Chemistry Regents	Balloon Arches	Question 23
	Balloon Arches	Question 26

Vocabulary

Terms from the Chemistry Glossary that come from this standard or from the released exam questions that assess it.

From this standard

• Boyle’s Law
• claim
• combined gas law
• design solution
• evidence
• gas
• high temperature
• ideal gas
• investigation
• low pressure
• mathematical representation
• matter
• molar quantity
• pressure
• properties
• real gas
• standard temperature and pressure (STP)
• temperature
• variable
• volume

From released exam questions

• molar mass – June 2026
• product – June 2026
• reactant – June 2026
• reaction – June 2026
• solid – June 2026
• solution – June 2026
• substance – June 2026

Performance Level Descriptions

Every Regents exam question on HS-PS1-9 is written to match one of the performance level descriptions (PLDs) below.

Level 1: Use data/information to identify the relationship between two variables in the combined gas law when the third variable and molar quantity are held constant. June 2026 · Q23

Level 2: Given data, construct a mathematical representation and/or calculate the value of an unknown variable in the combined gas law when the molar quantity is held constant. Aug 2026 · Q42 June 2026 · Q26

Level 3: Use data/information that provides evidence to make and/or support a claim about the relationship between two variables in the combined gas law when the third variable and molar quantity are held constant. Aug 2026 · Q41

Level 4: Analyze data to support the claim that the combined gas law describes the relationships among volume, pressure, and temperature for a sample of an ideal gas.

Level 5: Plan and conduct an investigation to gather and analyze data that validates the claim that the combined gas law describes the relationships among volume, pressure, and temperature for a sample of an ideal gas

Notice: PLD levels!

Resources

Examples and discussion of resources for the learning, teaching, and assessment of HS-PS1-9.

This section could be expanded upon. You can help out by adding to this section.

NGSS Dimensions

Performance expectation HS-PS1-9 was developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

• Analyzing and Interpreting Data
  • Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims or determine an optimal design solution.

Disciplinary Core Ideas

• PS1.A: Structure and Properties of Matter
  • (NYSED) The concept of an ideal gas is a model to explain behavior of gases. A real gas is most like an ideal gas when the real gas is at low pressure and high temperature.

Crosscutting Concepts

• Patterns
  • Mathematical representations can be used to identify certain patterns.

Page contributors: Conrad Richman, Caroline Leonard

Chemistry | HS. Structure and Properties of Matter