Which example shows that electromagnetic waves can travel without moving through a specific material (medium)?

A.
visible light through a prism

B.
sound traveling through a steel beam

C.
X rays through skin and muscle

D.
light passing through a vacuum tube

Question

Which example shows that electromagnetic waves can travel without moving through a specific material (medium)? 	
	
 
A.
	visible light through a prism
	
 
B.
	sound traveling through a steel beam
	
 
C.
	X rays through skin and muscle
	
 
D.
	light passing through a vacuum tube

anonymous · Answer

@Destinymasha & @AntiNode : )

anonymous · Answer

I think that the answer is D? 
but I'm not sure...

anonymous · Answer

d?

destinymasha · Answer

;i think so ......the opening of the tube :}

anonymous · Answer

when they said that no medium, I always think of vacuum immediately...

anonymous · Answer

that's what I thought because electronic waves is light and vacuums

anonymous · Answer

true,...

anonymous · Answer

thanks @Destinymasha and @AntiNode

anonymous · Answer

is it right?