I'm not sure what's the correct answer:

9)Which of these characteristics can only be attributed to a wave of red light?
A)The energy of the wave travels in the same direction as the wave travels.
B)The wave travels by vibrating the particles of the medium at a high rate.
C)The wave travels by compressing and expanding the medium it travels through.
D)The energy of the wave moves perpendicular to the direction the wave travels.

Ans: D

11) In which medium would sound travel the fastest?
A)across a room
B)in a swimming pool
C)through outer space
D)through a railroad track

Ans: A
12) Why do electromagnetic waves not require a medium for travel?
A) because electromagnetic waves travel too fast for stationary particles to move with them

B) because electromagnetic waves transmit energy without compressing the particles of the medium

C) because electromagnetic waves generate their own particles for compression and use these for movement

D) because electromagnetic waves move in two-dimensional space, the particles of mediums exist in 3-D space

Ans:

1 answer

wrong, wrong, B.
the first two, look at a, b.