Standard Level Content
Unit 2 · IB Chemistry
Particulate Nature of Matter
Investigation of the physical states of matter and the kinetic molecular theory that explains thermal properties and phase changes.
Lesson Slideshow Section 01
Unit Summary Section 02
Key Concepts
States of Matter, Kinetic Molecular Theory, Phase Transitions, Pure Substances vs Mixtures
Assessment Objectives
Describe states of matter, Explain phase changes via KMT, Distinguish between mixtures
Prior Knowledge Needed
Particle model of matter, basic heating/cooling curves
IB Syllabus Reference
S1.1
Interactive Study Guide
Click here to view the full, detailed topic summary for this unit.
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Cu
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Video Lesson Section 03
Video Instruction
2 Lessons Available
Atomic Models_Phase Diagrams
Particulate Nature of Matter_Isotopes
Practice Quiz Section 04 · Interactive
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Ne
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Vocabulary Review Section 05
Kinetic Molecular Theory
Model describing gas particles as being in constant, random, straight-line motion.
Internal Energy
The total of all kinetic and potential energies of the particles in a system.
Temperature
A measure of the average kinetic energy of the particles in a sample.
Ideal Gas
A theoretical gas that perfectly follows the gas laws, assuming no intermolecular forces and negligible particle volume.
Homogeneous Mixture
A mixture that has the same uniform appearance and composition throughout.
Heterogeneous Mixture
A mixture that consists of visibly different substances or phases.
Pure Substance
A type of matter with a fixed chemical composition and distinct properties (Elements or Compounds).
Sublimation
The phase transition where a solid changes directly into a gas without passing through the liquid state.
Avogadro’s Hypothesis
Equal volumes of gases at the same temperature and pressure contain the same number of particles.
Diffusion
The net movement of particles from an area of high concentration to an area of low concentration.
Effusion
The escape of gas particles through a tiny hole into a vacuum.
Compressibility
The capacity of a substance to decrease in volume under pressure.
Boyle’s Law
The pressure of a gas is inversely proportional to its volume at constant temperature ($P_1V_1 = P_2V_2$).
Charles’s Law
The volume of a gas is directly proportional to its absolute temperature at constant pressure ($V/T = k$).
Gay-Lussac’s Law
The pressure of a gas is directly proportional to its absolute temperature at constant volume ($P/T = k$).
Critical Temperature
The temperature above which a gas cannot be liquefied, regardless of the pressure applied.
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Revision Notes Section 06
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Practice Tests Section 07
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Worksheets & Labs Section 08