Why does sound need a medium to travel?
A. The particles slow down.
B. Empty space makes the sound travel faster.
C. The particles must transfer energy through
direct contact.
D. The frequency of sound requires a medium.

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water

Suppose you could go back in time to interview henri becquerel on the day he discovered radioactivity. from his perspective, write an account of the discovery.