Whats the difference between crack and cocaine?

Crack comes in the form of a white crystal rock; while cocaine comes in the form of a white powder. Cocaine is a type of illegal drug derived from coca leaves. This drug distorts the body’s sense of movement and pleasure as well as gives off feelings of euphoria and energizes the body. Cocaine can be snorted or injected. Crack, a freebase form of cocaine, is smoked.

can you list the answers so i can answer

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.