A piece of ice with a mass of 12.5g at 0 °C is dropped into a calorimeter cup with 100. g of liquid water at 20.0 °C. After the ice melts completely, the final temperature inside the calorimeter is 10.0°C. The specific heat of water is 4.184J/g.°C.
Which substance lost heat?
Which substantive gained heat?
What is the change in temperature?
How much heat did the water lose?
What is the best of fusion?

it can be icreased by increasing pressure.

c, liquids evaporate, creating a gas

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.