25cm3 of gas at 1 atm has a temperature of 20 degree celsis . When the gas is compressed to 20cm3, the temperature of the gas increase to 28 degree celsis.
Calculate the final pressure of the gas?​

1.28 atm

Explanation:

To solve this problem, you need to use the gas laws, more specifically the Combined Gas Law. It is P1V1/T1 = P2V2/T2. Simply plug your values in. But be careful! Make sure you convert your 20 degree C and 28 deg C to Kelvin, as that it the only temperature scale the Gas Laws work with. Upon plugging in your values, you get approximately 1.28 atm.

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.