The molecular formula for caffeine is c8h10n4o2. which of the following elements is not found in caffeine? carbon helium nitrogen oxygen

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

The number of moles of a given mass of a substance can be found without knowing its molecular formula or molar mass. true false

If you try to move a piano and are unable to move it, did you perform any work in the scientific sense of the word? yes? or no? this question is worth 20 points! let it be correct!