Thermometer is a device made of a sealed glass cylinder, containing a clear
liquid (water, for example), and several floating glass bubbles, each filled with a
different color liquid, and a small metal tag hanging from it.
represents a certain temperature (which is indicated on the metal tag).
All the bubbles are produced, and filled with liquid, so to have the same density (mass-to-volume ratio).
The metal tags, being of very similar volume to each other, are slightly different by weight, so that the bubbles+tags, are different very slightly from each other in their "average density", yet, being very close to that of the surrounding water.
As the temperature changes, some of the bubbles are floating at the top part of the cylinder, while others are sinking at the lower part of it.
The lower bubble of the floating ones (the one closest to the middle section of the tube) indicates the room temperature
Lovelyselectedtopicespecially in light oftheuse ofscientific knowledgefor use indesign. I thinkdistractorsare written ina waythat canlead to mistakes,if we considerthelevel of knowledgerequired ofjunior high school.Should perhapsrefine thewording. In addition, Ithink you wantthe linkcontainsinformationthat couldhelp resolvethe question.
This question is very interesting and well formulated. I wonder though
whether it’s not too difficult for children; they might find it hard to
identify the correct answer.
The geographical point is relevant to the question, but the author
might add there more information pertaining to the question. The remark
contained in the point mentions Archimedes, while the questions deals not only
with density but also with temperature (a subject which has nothing to do with
Archimedes), so the author might consider discussing this aspect too.
A correction: Syracuse is not in Greece, it’s in Sicily; the
confusion might arise from the fact that the region of Sicily and southern
Italy was once called “Magna Graecia”.