As any type of waves travels a medium, what is true about the particles in the medium?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains

What is the percentage of hydrogen in c2h4