Anderer Ressourcentyp

Siemens Stiftung

Not all shade is the same (hints)

Incremental hints:
The six hints and answers for the worksheet of the same name prepared for printing. The last hint presents the complete solution.

Working with incremental hints allows weaker students to develop a solution independently, helping them gain a sense of achievement and experience learning success. The document provides assistance related to the content and learning strategy for solving the task from the worksheet of the same name.

Information and ideas:
The students who did not use the hints to solve the task should also read the last hint with the complete solution to compare their results.
The hints in the prepared tasks have been designed so that they can be printed double-sided. Additional information on how the hints are used is compiled in the teaching methods named "Tasks with incremental hints - An introduction? that are available on the media portal.

Arbeitsblatt

Siemens Stiftung

A2 Is the heat pack a heat store? (worksheet 3)

Worksheet for subject teaching in English:
For the student experimentation instructions of the same name. Methodology tool: picture sequence / cloze test developed by Josef Leisen and Heinz Klippert.

Note: This worksheet has been developed especially for subject teaching in English and for language-sensitive subject teaching. It uses the picture sequence and cloze test methodology tools developed by Josef Leisen and Heinz Klippert. The picture sequence is used to train students how to correctly comprehend and then explain the chronological and logical sequences of events. The cloze test is used to review and summarize a topic. It is also suited for internal differentiation.
Students whose native language is not English and who do not have strong English skills receive support and training in understanding the technical vocabulary. They work with the specialized vocabulary and in this way acquire the ability to communicate about specific subjects.


Dieses Material ist Teil einer Sammlung

Bild

Siemens Stiftung

Phase diagram of water

Diagram:
A P-T diagram for pure water. The lines indicate the temperature and the pressure at which the solid, liquid, and vapor phases exist in equilibrium. All three phases exist in equilibrium only at the triple point; otherwise, there are a maximum of two phases.

In addition to the equilibrium curves (melting pressure curve, sublimation curve, vapor pressure curve), the diagram also includes the pressure and temperature data for the melting, boiling, triple, and critical points.
Attention: The axes of the diagram are not shown true to scale.

Information and ideas:
This diagram also reflects the density anomaly of water (lower density in the solid state than in the liquid state): The melting pressure curve shows a negative slope. The reason for the density anomaly is the hydrogen bonds.

Simulation

Siemens Stiftung

Phase transition due to pressure

Simulation:
The state of a substance depends not only on the temperature but also on the pressure. An example of this is skating on ice.

Ice skaters concentrate their body weight on a very small surface (2 thin blades). The resulting pressure (= force per surface area) liquefies the ice of the top layer. At microscopic level, this means that the water molecules are separated from their atomic binding partners inside the ice. The resulting thin film of water enables the skater to glide over the ice. The simulation shows this effect.
The whole process is augmented by a temperature effect: The sliding friction of the blades on the ice results in a very small amount of heating, which allows the ice to melt even more readily.

Information and ideas:
Ice researchers still do not always agree absolutely in which cases pressure is the dominant effect when skating on ice and in which cases friction. Scientific studies are still being carried out on this subject.
Assignment: Students should explain the melting process due to pressure using the p-T diagram.

Simulation

Siemens Stiftung

; Physics and chemistry of water: Energy storage and release using water as an example

Simulation:
Principle of energy storage and release with water as example, animated presentation.

Strictly speaking, energy is stored not only in molecular movements and vibrations but also in the transition between physical states. During evaporation and condensation, water absorbs and releases a relatively large amount of energy owing to the strong hydrogen bridge bonds.

Information and ideas:
As background for the topic "water as a means of energy storage" and "water in power generation", which is also important for thermal power engines, such as the steam engine. Even without going into thermodynamics, it is clear where steam engines get their energy from: The superheated steam contains a great deal of energy. Given the same volume, this corresponds to a high pressure that can move a piston.

Anderer Ressourcentyp

Siemens Stiftung

A4 Evaporation heat (answer sheet)

Answer sheet:
For the student experimentation instructions of the same name.

The answer sheet contains sample answers to all questions asked in the student experimentation instructions. In some cases, the answers are very short, often only in the form of key words. Depending on the learning objective, they can be augmented and enlarged upon with additional material from textbooks or Internet research.
Likewise, the answer sheet will be elaborate on the analyses for the individual subexperiments, but only in cases where experience shows that there could be difficulties.

You will find more detailed information in the related experimentation instructions "A4 Evaporation heat (student instructions)", which are available on the media portal of the Siemens Stiftung.

Anderer Ressourcentyp

Siemens Stiftung

A2 We store heat (link list)

Link list:
Further information on the experiment "A2 We store heat - From heat store to molten salt".

The links can be used for preparing or for further study of experiments from Experimento | 10+.

Experiment

Siemens Stiftung

A2 Storing heat (teacher instructions)

Experimentation instructions for Experimento | 10+:
Background information on the content and practical information on conducting the experiment "We store heat - From heat store to molten salt". This experiment comprises four subexperiments.


Enough apparatus and materials are supplied to allow eight groups of students to conduct the ex-periments simultaneously. When all the subexperiments are conducted in the suggested se-quence, they form a basis for a learning unit on heat, heat storage, temperature, phase transition (states of matter), heat of fusion, and latent heat. These instructions provide explanatory notes and ideas for further study.

The experiment comprises four subexperiments:
· Water as a heat store - Not only the tea gets cold
· Water as an effective heat store - Water can stay hot longer if ?
· Heat for cold fingers - Is the heat pack a heat store?
· How the heat pack stores heat - A salt that changes between solid and liquid states

Notes:
· Observe the safety information in the instructions as well as the applicable safety guidelines for your school.
· All materials mentioned in the instructions will have to be purchased directly from commercial sources.

Anderer Ressourcentyp

Siemens Stiftung

How does "freeze-drying? work? (hints)

Incremental hints:
The six hints and answers for the worksheet of the same name prepared for printing. The last hint presents the complete solution.

Working with incremental hints allows weaker students to develop a solution independently, helping them gain a sense of achievement and experience learning success. The document provides assistance related to the content and learning strategy for solving the task from the worksheet of the same name.

Information and ideas:
The students who did not use the hints to solve the task should also read the last hint with the complete solution to compare their results.
The hints in the prepared tasks have been designed so that they can be printed double-sided. Additional information on how the hints are used is compiled in the teaching methods named "Tasks with incremental hints - An introduction? that are available on the media portal.

Arbeitsblatt

Siemens Stiftung

Not all shade is the same (task)

Worksheet:
On hot days, why is it cooler in the shade of a tree with a thick canopy of leaves than under a patio umbrella? Task with a contextual scenario.

A short story leads to the task?s question. The students should explain why it is cooler in the shade of a tree with a thick canopy of leaves than under a patio umbrella covered with fabric. The question can be answered based on the energy balance during the transition between the states of aggregation; in this example, the transition is the evaporation of water from the leaves of a plant.

Incremental hints for answering this task are available under "Not all shade is the same (hints)? on the media portal of the Siemens Stiftung.
Explanations of the experiment for the teacher are found in "Not all shade is the same (teacher information).?