How are food and oxygen made during the process of photosynthesis​

Plants take in the light from the sun, water from the soil in the ground, and carbon dioxide from the air around it and converts it to food and energy for itself and oxygen for the animals and humans around it. This is often perceived as plants "breathing in carbon dioxide" and "breathing out oxygen"

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.