Kinetic Theory
Übersicht
Stand a pan of crushed ice on a hot ring with a thermometer in it and watch the reading. It climbs to zero and then it stops. The ring is still glowing, the ice is visibly turning to water, joules are pouring in at hundreds every second, and the number on the thermometer refuses to move. It stays there for minutes. Only when the last sliver of ice has gone does the reading start to rise again, and later, at one hundred, it stalls a second time and stays stalled while the pan boils dry. Two flat stretches in one heating, and in both of them energy is arriving with nothing to show for it on the scale.
Nothing has gone missing. This lesson shows you where those joules went, and it hands you a way of reading any temperature against time graph as a story about particles: how far apart they are, how fast they move, and how tightly they are held to each other. You will compare the three states in one model, define specific heat capacity and put numbers into the equation that goes with it, learn to say in words exactly what is happening along a flat section of a graph, find out what impurities do to a melting point and a boiling point, and finish by cooling molten stearic acid in a test tube and watching one of those flat stretches appear in reverse on your own results.
Ziele
- Kinetic theory can be used to explain the different states of matter and their properties. The particles in solids, liquids and gases have different amounts of energy. Students should be able to recognise, use and compare simple diagrams to represent key features of solids, liquids and gases.
- The specific heat capacity of a substance is the amount of energy required to change the temperature of one kilogram of the substance by one degree Celsius. The relationship between energy, E, mass, m, specific heat capacity, c, and temperature change, ∆θ, is: e.The melting point of a solid and the boiling point of a liquid are affected by impurities. Required practical: Investigate cooling curves for stearic acid. Throughout Section 3.4, students should be able to explain the shape of the temperature-time graph for a substance that is either cooled or heated through changes in state.
Mindmap
Dieses Thema ist als Karte dargestellt, damit die Zusammenhange sichtbar werden.
Mindmap in der App offnen
Lernkarten
Schnelles Abfragen der Fakten, die zu diesem Thema gepruft werden.
Diese Karten in der App uben
Lektionshinweis
Vollstaendige Lernnotiz in der Green Bridge App
Holen Sie sich die Green Bridge CBT App auf Handy oder Computer fuer die komplette IGCSE-Bibliothek: fruehere Pruefungen, Bewertungsschemata, Mindmaps, Lernkarten und Audiolektionen.
Unterrichtsbewertung
Herzlichen Glückwunsch zum Abschluss der Lektion über Kinetic Theory. Jetzt, da Sie die wichtigsten Konzepte und Ideen erkundet haben,
Sie werden auf eine Mischung verschiedener Fragetypen stoßen, darunter Multiple-Choice-Fragen, Kurzantwortfragen und Aufsatzfragen. Jede Frage ist sorgfältig ausgearbeitet, um verschiedene Aspekte Ihres Wissens und Ihrer kritischen Denkfähigkeiten zu bewerten.
Nutzen Sie diesen Bewertungsteil als Gelegenheit, Ihr Verständnis des Themas zu festigen und Bereiche zu identifizieren, in denen Sie möglicherweise zusätzlichen Lernbedarf haben.
- Which statement describes the particles in a liquid? A. Held in fixed positions in a regular arrangement B. In contact with one another but free to slide past each other C. Widely separated and moving quickly in random directions D. Widely separated and held in fixed positions Answer: B
- What is the unit of specific heat capacity? A. J B. J/kg C. J/kg/degC D. degC/J Answer: C
- The specific heat capacity of water is 4200 J/kg/degC. How much energy is needed to raise the temperature of 2.0 kg of water from 15 degC to 35 degC? A. 42 000 J B. 84 000 J C. 168 000 J D. 294 000 J Answer: C
- A pure substance is heated steadily and its temperature stays constant for several minutes. Which statement is correct for that period? A. No energy is being transferred to the substance B. The energy transferred is increasing the average speed of the particles C. The energy transferred is separating the particles as the substance changes state D. The energy transferred is being destroyed Answer: C
- Salt is dissolved in a beaker of pure water. What happens to the freezing point and to the boiling point of the water? A. Both are lowered B. The freezing point is lowered and the boiling point is raised C. The freezing point is raised and the boiling point is lowered D. Both are raised Answer: B
Bearbeiten Sie diese Fragen in der App
Bearbeiten Sie diese Fragen in der App
Empfohlene Bücher
Weiterlernen mit offenen Quellen
-
Lehrbuchabschnitt
Temperature Change and Heat Capacity
One of the major effects of heat transfer is temperature change: heating increases the temperature while cooling decreases it. We assume that there is no phase change and that no work is done on or by the system. Experiments show that the transferred heat depends on three factors—the change in tempe
"College Physics: Temperature Change and Heat Capacity" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/14-2-temperature-change-and-heat-capacity. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
-
Lehrbuchabschnitt
What Is a Fluid?
Matter most commonly exists as a solid, liquid, gas, or plasma; these states are known as the common phases of matter . Solids have a definite shape and a specific volume, liquids have a definite volume but their shape changes depending on the container in which they are held, gases have neither a d
"College Physics: What Is a Fluid?" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/11-1-what-is-a-fluid. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
Von anderen Organisationen unter offenen Lizenzen veröffentlicht und wie gewünscht genannt. Links öffnen deren Websites.
Übungsklausuren üben
Möchten Sie Übungsklausuren zu Kinetic Theory üben? Laden Sie die Green Bridge CBT App herunter, um Übungsklausuren und vollständige Prüfungssimulationen zu diesem Thema zu erhalten.
Lade die App im Google Playstore herunter.
Alles, was du brauchst, um in JAMB, WAEC & NECO zu glänzen.
