When the Statue was unveiled in 1886, it was a shiny brown color, like a penny. The reason the Statue of Liberty changed colors is that the outer surface is covered with hundreds of thin copper sheets. Copper reacts with the air to form a patina. This is an example of a . Physical Change
Chemical Change
Chemical Property
Physical Property

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.

the answer is c.the valence of the atoms combine .

answerleaving cheese out to get moldy;