I need help, I'm scared of failing chemistry and I have nowhere else to go for help. Here are the problems that I need solved. https://paste. pics/FAJCM
https://paste. pics/FAJD2
https://paste. pics/FAJE2
For the first 2 please put the answers as Na+1-(answer)=N-3 so that I know which questions the answers are for. And thank you to whoever answers this because you're a life saver.

i just learnt this recently but i need to look through my notes again

10 years is the 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.