For a quiz, ! : ) how did early chemists determine which substances were elements? a. they knew what substances were mixtures. b. they knew how many protons were in the atoms. c. they knew which substances could not be broken down by chemical means. d. they knew how many electrons were in the outer shell of every atom

did anyone actually do this? like if anyone has submitted this i rly need .

what does the table look like

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.