What to do with this activity?

This is a simple science experiment that will show your child how sound changes depending on how full something is (volume). You will need 6 same-size glass bottles (the bigger the better); a large jug of water; labels to number the bottles; and a spoon to act as a striker.

1) Line up the 6 bottles in a safe solid place - maybe on a waterproof floor - and label them 1 to 6 from left to right. 

2) Fill up bottle 1 with water; pour a little less water into bottle 2; even less into bottle 3; and so on, until bottle 1 has only a very small amount of water. 

3) Now "tune" the bottles by pouring water out, or adding water, to make it sound like a scale (think "do-re-mi-fa-so-la", as in the song "do, a dear, a female deer"). Bottle 1 will be the lowest note, and bottle 6 will be the highest note.

4) Play tunes by gently hitting each bottle with the spoon. Check out the PDF above right for some tune suggestions. 

Notice how, the more water there is in the bottle, the lower the note becomes. This is because, when you hit the glass, both glass and water vibrate. A bigger volume of water makes a lower sound.

Talk about how large musical instruments, like double basses, play low notes, and small musical instruments, like tin whistles, are very high-pitched.