Could tests be performed to support the clamim?

Asample of a gaseous substance changes into a liquid

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

5. why should the electrons be placed separate from each other (why not together)?