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Weighing needs practice, make your own weights
Matter - the subject of
chemistry - is characterized by a volume and a mass: Volumes were measured
by a syringe, masses are measured by scales.
Photo 1: Weighing
was invented more than 5000 years ago. These two men depicted at the wall
of a mastaba in Saqqara are weighing gold and reporrting the results on
a papyrus.
Such scales are still available
in most schools in Germany. Photo 2: They are still available
produced in Egypt.
In the following experiment
you learn how to handle such a scale and produce your own weights.
Material
Egyptian two-pan scale,
aluminium foil, metal closures of Liquemin
ampoules, inswulated copper wire ( 2x0,6 mm D, red/white PVC isolated,
20 m, about 130g), Cola can made of steel, scissors (2 graduated 1-gram
weights, 1 Yen coins, different other coins,
syringe with exactly 1.0 mL of water.
..
Experiment
Photo 3 and 4: Make
weights from insulated copper wire or Cola can metal (1 g, 200 mg, 100
mg, 50 mg)
1. Tare the scale by
lining the pans with aluminium foil.
2. Make 1.0-gram weights
from copper wire, bisect some of them, divide them into smaller pieces,
twist them around pencils or mails (photo 3).
3. Weigh 1 Yen and other
coins, Liquemin metal closure using your self-made weights.
4. Write down your results:
Mass of 1/ 2 / 5 Cent (....... g /........ g/........ g), 1 Yen (........
g), 1 Liquemin closure (........ g).
Weights made of Cola can
metal (Photo 4 ), of chequered paper
or aluminium foil are also useful.
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on..........................................................................................last
modification: 25.10.2004