A believe that’s called a reference point.
The number we need in order to answer the question belongs in the space between the words "is" and "of". You left that blank blank, so there really isn't any question here to answer.
HOWEVER ... the refractive index of a medium can never be less than 1.0 , so we know for sure that <em>choice-a can't be</em> the correct answer.
A-200 kg
I hope this helped xx
The molecules of a solid vibrate faster so that they start spreading out to become a liquid. This energy makes them vibrate faster so the bonds between molecules can't interact all that well anymore creating more distance. The stronger the bonds between the molecules the higher the energy (temperature) has to be to get them away from each other. Hope I didn't confuse you too much!
I would say your answer to this question would be D
