Why must labs that use mercury thermometers calculate Kelvin ?

Mercury and other liquid thermometers cannot be used to measure temperatures in kelvins. Kelvin thermometers are usually electric devices that can record tiny variations in radiation. These variations would not be visible and may not change air pressure enough to raise the level of mercury in a liquid thermometer

Explanation:

because those are the only thermometers that are truly accurate for kelvins

Explanation:

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.