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1 ALL MATTER IN THE UNIVERSE IS MADE OF VERY SMALL PARTICLES
- Theory
- TASKS
- 3.1 We observe and study substances
- 3.2 Water is not only for drinking
- 3.3 The air around us
- 3.4 Metals in our life
- 3.5 Light
- 3.6 Physical qualities (volume, force, time, weight)
- Task 1: Measure the volume of liquid, powdered and solid substances with a graduated cylinder made of a PET bottle
- Task 2: Measure the volume of the lungs by so-called spirometer made from a PET bottle
- Task 1: Make a scale from a ruler
- Task 1: Make a paper sundial
- Task 2: Make a paper sundial in the garden
- Task 1: Make a dynamometer for measuring the tension force
- Task 2: Make a dynamometer for measuring the press
- WORKSHEETS FOR PUPILS
- Workshops
We observe and study substances
Vaporisation
Vaporization is a process when liquid state changes into gaseous. It is causedby escape of a molecule of a substance from liquid phase to gaseous phase. Molecules in a liquid move freely and in a disorganized way. When they reach a certain speed they are able to „escape“, they leave the surface of the liquid as gas molecules.This process is called vaporization. Various liquids, despite the same conditions, evaporate at different speeds. Acetone evaporates very quickly; alcohol evaporates a little slower and water the slowest. Liquids which evaporate quickly are called volatile. The speed of evaporation depends on the boiling point of a liquid. A tabulated value of acetone boiling point is 56 °C, ethanol 78 °C and water 100 °C.Liquid which is evaporating, takes in the warmth from its surroundings and due to this it cools down its surroundings. Therefore a thermometer which is wrapped in a piece of cotton wool and soaked in the most volatile liquid, will measure the lowest value.