What did Dalton's atomic theory teach? A. The smallest unit of matter is the atom.
B. Atoms can be split into even smaller particles.
C. All matter comes from one kind of atom.
D. All science can be explained by the existence of atoms.

C. All matter comes from one kind of atom

I think

Explanation:

a polar bond is formed when electrons are shared unevenly between atoms

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.