Question 25 of 30 Which statement about balanced chemical equations is true?
A. The total number of moles of products equals the total number of
moles of reactants.
B. The mass of the products is greater than the mass of the
reactants when the number of moles increases.
O C. The mass of the new atoms that are formed equals the mass of
the atoms that made up the reactants.
D. The total mass of the reactants equals the total mass of the
products.

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.