In the molecule SCl2SCl2, sulfur makes two covalent bonds. Therefore, two of its six valence electrons need to be unpaired. The orbitals with the same energy are known as degenerate orbitals. For example, the p subshell has three degenerate orbital, namely, pxpx, pypy, and pzpz. How many degenerate orbitals are needed to contain six electrons with two of them unpaired

the answer is option a.

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.