From  VDOE's Curriculum Framework (a student friendly version is located on the activity page in the Study Guide for each standard)
Standard 5.2 - Sound
The student will investigate and understand how sound is transmitted and is used as a means of communication. Key concepts include
a) frequency, waves, wavelength, vibration;
b) the ability of different media (solids, liquids, and gases) to transmit sound; and
c) uses and applications (voice, sonar, animal sounds, and musical instruments).

The concepts developed in this standard include the following:
Sound is a form of energy produced and transmitted by vibrating matter.
Sound travels in waves and can be described by the wavelength and frequency of the waves. A wave is a disturbance moving through a medium (solid, liquid, or gas).
The frequency of sound is the number of vibrations in a given unit of time.
Sound is a compression wave moving outward from its source. The wavelength of sound is the distance between two compressions.
Pitch is determined by the frequency of a vibrating object. Objects vibrating faster have a higher pitch than objects vibrating slower.
Sound travels more quickly through solids than through liquids and gases because the molecules of a solid are closer together. Sound travels slowest through gases because the molecules of gases are farthest apart.
Some animals make and hear ranges of sound vibrations different than humans can make and hear.
Musical instruments vibrate to produce sound.

In order to meet this standard, it is expected that students should be able to:
use the basic terminology of sound to describe what sound is, how it is formed, how it affects matter, and how it travels.
create and interpret a model or diagram of a compression wave.
explain why sound waves travel only where there is matter to transmit them.
explain the relationship between frequency and pitch.
design an investigation to determine what factors affect the pitch of a vibrating object. This includes vibrating strings, rubber bands, beakers/ bottles of air and water, tubes (as in wind chimes), and other household materials.
compare and contrast sound traveling through a solid with sound traveling through the air. Explain how different media (solid, liquid, and gas) will affect the transmission of sound.
compare and contrast the sounds (voice) that humans make and hear to that of other animals. This includes bats, dogs, and whales.
compare and contrast how different kinds of musical instruments make sound. This includes string instruments, woodwinds, percussion instruments, and brass instruments.