Which waves can travel through empty space?
A. Light waves
B. Water waves
C. Sound waves
D. Mechanical waves

If you want to change the pitch of a sound, you have to change the

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

The material that keeps its new shape after it is stretched is called?