The image above shows a chamber with a fixed volume filled with gas at a pressure of 1560 mmHg and a
temperature of 445.O K. If the temperature drops to 312.0 K,
what is the new pressure of the gas in the chamber?

the correct answer is:

a. formation of precipitation

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.