Learning Path

In all three sub-units, students are introduced into some basic chemical knowledge about structure-property relations, they are equipped to enhance that knowledge based on further investigations, and they are invited to become creative about thinking of new products or ways of presenting ideas to others.

Sub-unit 1 offers basic knowledge on approaches to describe, to structure and to systemize “chemical substances” that students can find at home.

In a second phase, they carry out experiments to deepen their knowledge on properties and behaviour of such substances in different environments, e.g. by mixing them or changing conditions such as the temperature. They should develop a deeper knowledge e.g. on systematic tests of solubility (salt / oil / coffee in water), heatability (salt, sugar water), effects on organism (bacteria, skin) etc. From this, they can draw conclusions about safe treatments which they are invited to present in the third phase.

Sub-unit 2 wants to engage the students in using and enlarging their chemical (and biological) knowledge for the explanation of processes related to cleaning demands in the household. As this might not always be an encouraging topic for 13-14-year-olds, the sub-unit describes several stimulating and sometimes maybe surprising experiments that the students can carry out themselves.

The basic background they should build up throughout the sub-unit is led by the question of how to classify dirt they can see and “dirt” they cannot easily find, such as bacteria. They shall be able to differentiate between hydrophilic and hydrophobic dirt (polarity of structures), living dirt (protein membranes of bacteria), fibre dirt (basic structures and functional groups / reactivity); different cleaning agents such as water / acids / bases / alkanes / acetone (classification).

They should enlarge their knowledge by carrying out experiments to investigate interaction between dirt and cleaning detergents, and they should interpret their findings based on what they had learned about solubility and reactions with focus. On the sub-microscopic level, they should use models about inter- or intramolecular bonding and reactions.

In the third phase, the students are invited to create “the optimal cleaning agent”, designing a product and a strategy to sell it and explain its properties according to its chemical functionality for different situations and environments.

Sub-unit 3 lays or enhances a content knowledge background on fibres used in clothes. The students will analyse structures and properties and will learn how to classify polymers. They investigate different fibres in different products, e.g. the effects of weather (water, temperature), skin (moisture, temperature, skin) and washing detergents (different ingredients, temperature).

The investigations and the discussion of results shall lead to a deeper understanding of structure-property-relations in changing environments, applying model-based explanations and systematic series of experiments along the IBSE structure.

In the closing phase of the sub-unit, the students are invited again to become creative: They should invent “the dream fibre” or “the dream detergent” with argumentations based on structure-property-knowledge, IBSE structure for engineers, and STS arguments.

Student Learning Activities