CLASS 5 · LEARNING KNOWLEDGE
Water as a substance – basic principles
How it works
Water is a chemical compound with the formula H2O and occurs in nature as a liquid, a solid (ice) and a gas (water vapour). It has typical properties such as odourlessness, colourlessness and a boiling point of 100 °C at normal pressure. Water is an important solvent and plays a central role for living things and the environment. It can dissolve substances, transport them and release them again. The water cycle describes the constant movement of water between the atmosphere, land and oceans.
Note
Pure water is a substance with characteristic properties and can occur as a solid, liquid or gas. If water dissolves other substances, a mixture is formed; the water remains the same substance, and the dissolved substances can be removed again by suitable separation methods.
Pure water is a substance with characteristic properties and can occur as a solid, liquid or gas. If water dissolves other substances, a mixture is formed; the water remains the same substance, and the dissolved substances can be removed again by suitable separation methods.
An example
Which property applies to pure water?
Pure water is colourless because it contains no dyes and does not absorb visible light.
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Chemistry. The topic assignment may vary by federal state.