https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/thermal-expansion-theoretical 2026-04-08T01:15:04.085520103Z Thermal expansion - theoretical Let's solve some problems to test our understanding of the theoretical aspects of thermal expansion. Aakash Bagga exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:states-of-matter/x2613d8165d88df5e:gases/e/apply-properties-of-gases 2026-04-27T14:30:54.817409388Z Apply: Properties of gases Apply your understanding of intermolecular forces to predict macroscopic properties in gases in this set of free practice questions. Donna Fig exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:states-of-matter/x2613d8165d88df5e:gases/e/understand-kinetic-molecular-theory 2026-04-29T07:20:45.495372596Z Understand: Kinetic molecular theory Check your understanding of the kinetic molecular theory of gases in this set of free practice questions. donna exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/effect-of-temp-and-pressure-on-state-change-pk 2025-12-18T00:30:56.558401705Z Effect of temp and pressure on state change Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Effect of temp and pressure on state change Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/m3IxzzbHcIc.mp4/m3IxzzbHcIc.mp4 321 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/explanation-thermal-expansion-of-liquids-ur 2025-08-08T00:24:37.843818748Z Explanation: Thermal expansion of liquids Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Explanation: Thermal expansion of liquids Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/zufhLCGKELI.mp4/zufhLCGKELI.mp4 64 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/activity-thermal-expansion-in-gases-ur 2025-08-07T18:49:36.591279888Z Activity: Thermal expansion in gases Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Activity: Thermal expansion in gases Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/ZAt3ugRB1Zo.mp4/ZAt3ugRB1Zo.mp4 40 Properties of solids, liquids and gases https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:thermodynamics/x2eef969c74e0d802:energy-of-phase-changes/v/enthalpy-and-phase-changes 2022-10-05T02:43:18.611402953Z Enthalpy and phase changes Energy is absorbed or released by a system undergoing a phase change. The energy changes for systems undergoing complementary phase changes are equal in magnitude but opposite in sign. For example, the molar heat of vaporization for water (corresponding to the transition from liquid water to gaseous water) is +40.7 kJ/mol, while the molar heat of condensation for water (corresponding to the transition from gaseous water to liquid water) is -40.7 kJ/mol. Jay video https://cdn.kastatic.org/ka_thumbnails_cache/79213b66-1851-41f8-b13e-cacebad3962c_1280_720_base.png Enthalpy and phase changes Energy is absorbed or released by a system undergoing a phase change. The energy changes for systems undergoing complementary phase changes are equal in magnitude but opposite in sign. For example, the molar heat of vaporization for water (corresponding to the transition from liquid water to gaseous water) is +40.7 kJ/mol, while the molar heat of condensation for water (corresponding to the transition from gaseous water to liquid water) is -40.7 kJ/mol. https://cdn.kastatic.org/ka-youtube-converted/jCKvxH5mXR4.mp4/jCKvxH5mXR4.mp4 193 Properties of solids, liquids and gases https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/states-of-matter/v/states-of-matter 2021-01-04T18:35:18Z States of matter Introduction to the states or phases of matter. Sal Khan video https://cdn.kastatic.org/googleusercontent/YJaya_goqyR9J2aMbNKVoorixkEPY67v6-XaZz_c82fZLwsShc2l8YSU2uyQyAyF44DHziJ1uPGfrgTy04dA_7s States of matter Introduction to the states or phases of matter. https://cdn.kastatic.org/ka-youtube-converted/pKvo0XWZtjo.mp4/pKvo0XWZtjo.mp4 1164 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/states-of-matter-ms 2025-02-13T17:59:34.347326855Z States of matter Matter exists in three main states: solids, liquids, and gases, each with unique particle arrangements and behaviors. Particles range from being tightly packed, with a definite shape and volume, to moving freely, with no fixed shape or volume. Understanding these states of matter helps us see why solids are rigid, liquids flow, and gases expand to fill spaces. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/cb816a21-25af-4ceb-9bcd-1a5bf80fc572_1280_720_base.png States of matter Matter exists in three main states: solids, liquids, and gases, each with unique particle arrangements and behaviors. Particles range from being tightly packed, with a definite shape and volume, to moving freely, with no fixed shape or volume. Understanding these states of matter helps us see why solids are rigid, liquids flow, and gases expand to fill spaces. https://cdn.kastatic.org/ka-youtube-converted/gBiF-OLUVTY.mp4/gBiF-OLUVTY.mp4 269 Properties of solids, liquids and gases https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:intermolecular-forces-and-properties/x2eef969c74e0d802:solids-liquids-and-gases/v/representing-solids-liquids-and-gases-using-particulate-models 2022-10-05T02:43:18.611402953Z Representing solids, liquids, and gases using particulate models In this video, we'll learn how to represent solids, liquids, and gases using particulate models. The particles in a solid are either highly ordered (if the solid is crystalline) or have no regular arrangement (if the solid is amorphous). In both cases, the motion of the particles is limited. The particles in a liquid are close together and are constantly moving and colliding. Finally, the particles in a gas are generally well-separated and are in constant, random motion. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/4afb6fa0-d848-4ae6-8e3f-41ea2c33569a_1280_720_base.png Representing solids, liquids, and gases using particulate models In this video, we'll learn how to represent solids, liquids, and gases using particulate models. The particles in a solid are either highly ordered (if the solid is crystalline) or have no regular arrangement (if the solid is amorphous). In both cases, the motion of the particles is limited. The particles in a liquid are close together and are constantly moving and colliding. Finally, the particles in a gas are generally well-separated and are in constant, random motion. https://cdn.kastatic.org/ka-youtube-converted/4Q45iIeMdCM.mp4/4Q45iIeMdCM.mp4 291 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/digging-deeper-into-gases-ur 2025-08-07T23:35:51.501752344Z Digging Deeper into Gases Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Digging Deeper into Gases Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/EGZPnk37dmk.mp4/EGZPnk37dmk.mp4 336 Properties of solids, liquids and gases https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/states-of-matter/v/states-of-matter-follow-up 2021-03-23T09:46:00Z States of matter follow-up More on plasma and hydrogen bonds. Sal Khan video https://cdn.kastatic.org/googleusercontent/7Y6Wjb8dz1EvWvAeTtROhREsfoz6SAObfOSuYzZjZt_qa4E7rMPSaWOSpSetQns3g9MC_z6PDHm02lnjgBP9n7w2 States of matter follow-up More on plasma and hydrogen bonds. https://cdn.kastatic.org/ka-youtube-converted/WenwtcuqOj8.mp4/WenwtcuqOj8.mp4 525 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/a/states-of-matter-and-phase-changes 2026-04-29T07:20:45.495372596Z Learn and try: States of matter and phase changes Learn about the three main states of matter and how particles behave differently in solids, liquids, and gases. Discover what happens during phase changes like melting and boiling and how energy affects these transitions. article https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/interparticle-forces-of-attraction-in-solids-liquids-and-gases 2026-04-20T07:20:46.893989224Z Interparticle forces of attraction in Solids, Liquids and Gases This Class 8 Science exercise on Interparticle Forces of Attraction explains why solids are rigid, liquids flow, and gases expand freely. With MCQs, dropdowns, and image-based questions linked to textbook experiments and daily life, it builds clear understanding step by step. Yajurva Joshi exercise https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:intermolecular-forces-and-properties/x2eef969c74e0d802:solids-liquids-and-gases/e/solids-liquids-and-gases 2023-08-07T17:25:22.494770007Z Solids, liquids, and gases Practice interpreting particulate models of solids, liquids, and gases in this set of free questions designed for AP Chemistry students. exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/why-water-vapor-exists-without-boiling-evaporation-vs-boiling-ur 2025-08-07T23:35:51.501752344Z Why Water Vapor Exists Without Boiling: Evaporation vs Boiling Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Why Water Vapor Exists Without Boiling: Evaporation vs Boiling Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/2754mmUsQqc.mp4/2754mmUsQqc.mp4 396 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/solid-liquid-and-gas 2026-04-28T11:00:37.315336883Z Solid, liquid and gas Let's try to distinguish between a solid, liquid and gas Vibhor Pandey exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:diffusion/e/states-of-matter 2026-04-27T11:50:44.5708213Z States of matter Lets answer some questions on states of matter Shankar R exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/apply-phase-changes 2026-04-29T07:20:45.495372596Z Apply: Phase changes Apply your understanding of phase changes in this set of free, standards-aligned practice questions. Allen Ruch exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/states-of-matter-bonus-video-pk 2025-12-18T02:00:41.510401167Z States of matter (Bonus video) Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw States of matter (Bonus video) Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/knOwSIDDAl4.mp4/knOwSIDDAl4.mp4 735 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/understand-phase-changes 2026-04-29T07:20:45.495372596Z Understand: Phase changes Check your understanding of phase changes in this set of free, standards-aligned practice questions. Allen Ruch exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/interconversion-of-states-of-matter 2026-04-20T07:20:46.893989224Z Interconversion of states of matter Lets answer some questions. Shankar R exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/changing-states-of-matter-part-1-ur 2025-08-07T23:35:51.501752344Z Changing States of Matter : Part 1 Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Changing States of Matter : Part 1 Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/NTi1aNW-iRU.mp4/NTi1aNW-iRU.mp4 413 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/changing-states-of-matter-part-2-pk 2025-12-18T00:30:56.558401705Z Changing States of Matter : Part 2 Cerated by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Changing States of Matter : Part 2 Cerated by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/dtp9wEXYi24.mp4/dtp9wEXYi24.mp4 361 Properties of solids, liquids and gases https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/e/understand-states-of-matter 2026-04-28T11:00:37.315336883Z Understand: States of matter Check your understanding of solids, liquids, and gases in this set of free, standards-aligned practice questions. Allen Ruch exercise https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:states-of-matter/x8bc8fb44369617ed:properties-of-solids-liquids-and-gases-untitled-lesson-7/v/phase-changes 2025-02-13T17:59:34.347326855Z Phase changes Phase changes are physical changes in which a substance shifts from one state of matter to another, like ice melting into water or water boiling into steam. These transformations depend on two factors: particle attractions and kinetic energy. Heating a substance increases particle motion, potentially overcoming attractions to change phases. Each substance has unique melting, freezing, and boiling points due to these forces. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/caa39295-8825-4f0c-8086-c97aa37e714f_1280_720_base.png Phase changes Phase changes are physical changes in which a substance shifts from one state of matter to another, like ice melting into water or water boiling into steam. These transformations depend on two factors: particle attractions and kinetic energy. Heating a substance increases particle motion, potentially overcoming attractions to change phases. Each substance has unique melting, freezing, and boiling points due to these forces. https://cdn.kastatic.org/ka-youtube-converted/Aeddl02frBE.mp4/Aeddl02frBE.mp4 458 Properties of solids, liquids and gases