In 1808, John Dalton proposed a series of statements regarding the atom that became known as Dalton's atomic theory. Since Dalton's original proposal, some of the statements have been updated or changed due to new discoveries. Which discovery is the reason why Dalton's assumption that all atoms of the same element have the same mass and other properties is no longer valid

where is the following

explanation:

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.

i belive it is water