You are most likely to see a rainbow when it's raining while the sun is shining. This typically occurs in the afternoon when the sun is lower in the sky and rain is present at a distance. The sunlight refracts, reflects, and disperses through raindrops, creating the spectrum of colors that form a rainbow. It's most visible when you are positioned with your back to the sun, facing the rain.
Most likely not, since the rainbow contains everypossible color that the human eye can detect.
Volcanoes are most likely to form at the edges of the tectonic plates.
More likely
Chlorine is most likely to form the chloride ion, which has a charge of -1.
A supersaturated solution is most likely to form crystals as it cools.
It most likely decended form soccer
Oxygen is most likely to form the oxide ion (O2-) by gaining two electrons.
The most likely conclusion is that it's usually wet in there, so maybe you don't want to brag about it.
Most likely you would either get black or brown.
Most likely
The sunlight has to be refracted by water drops in order for the sunlight to form a rainbow.