Sound

"materials may transmit, absorb, or reflect light sound carries energy
loud sounds carry more energy
forms of sound can be either audible and inaudible
sound is caused by vibrations in a medium
sound can travel through many substances (e.g., air, water, metal)
the shaking (oscillation) of objects is called vibrating
vibrations are measured in the number of oscillations per time (called the frequency)
higher (faster) the frequency corresponds to higher pitch sounds
lower (slower) the frequency corresponds to lower pitch sounds
materials may transmit, reflect, or absorb sound (an echo is reflected sound)
sound travels through gas, liquid, and solids"
Vocabulary: vibration, vocal cords, pitch, frequency, loudness, sound waves, reflect, absorb, transmit, echo
Sources: Mission Hill Elementary School
Changing Sounds interactive from BBC
The World of Science (children's reference book) from Parragon (section 4, page 109)

Light

"light carries energy
brighter light carries more energy
forms of light can be either visible or invisible
natural and artificial light have measurable properties (e.g., colour, wavelength, brightness)
light can travel in a straight path (rays) light rays change direction (bend, refract) as they pass from one medium to another"
vocabulary: reflect, refract, absorb, transmit, natural, artificial, light beam, transparent, translucent, opaque, spectrum
sources: Mission Hill Elementary School
How we see things interactive from BBC
The World of Science (children's reference book) from Parragon (section 4, page 109)
"The Amber Spyglass: How to see invisible light and the way scientists work" in The Science of Philip Pullman's His Dark Materials (part of this chapter is available through Google Books)

Rocks and minerals

Usborne Spotter's Guide for Rocks and Minerals
Rocks for Kids
Interactives Rock Cycle
Rocks interactive and quiz from BBC
Materials: sorter from Dollarama