Using this activity chart, which reaction will happen when a piece of copper is placed in a lead nitrate solution. 2cu + 3pb(no3)2 3cu(no3) 2 + 2pb no reaction occurs. 2cu + 3pb(no3)2 2cu(no3) 2 + 3pb 3cu + 3pb(no3)2 3cu(no3) 2 + 3pb the answer cannot be determined from the information given.

No reaction occurs.

Explanation:

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.

Copper lies lower in the reactivity series and thus is less reactive than lead. Only a more reactive element is able to displace a less reactive element from its salt solution. As copper is less reactive than lead , it cannot lose electrons and thus cannot displace lead.

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.