Lab Week #7 – Jr/Sr
Science
Sticky Water
Surface Tension
1) Fireworks MilkWorks
1.
2.
3.
4.
5.
6.
Fill a plate with milk
Place one drop of as many colors of
food coloring as you want into
the middle
Take a cotton-swab and dip one
end in soap
Place and hold the soapy end of the
swab in the middle of the food coloring
What happens? Why?
Keep your plate of milk for Part 2
2) Drops on Tops
1.
2.
3.
4.
5.
Use the plate of milk from Part 1 (the mixed colors don’t
matter)
Use the other end of the cotton swab (no soap) to flick tiny
drops across the surface
of the plate
You should see tiny
spherical balls of milk
How long do they last?
How can you make them
larger?
5) Sinking Paperclip
1.
2.
3.
4.
6) Coin Cup
1.
2.
3.
4.
3) Water Powered Boat
2.
3.
4.
5.
Cut out a simple boat
shape from paper
Float it on top of a plate
of water
Dip a cotton swab in
soap
Place the swab in the water behind your boat
What happens? Why?
4) Cup Upside-Down
1.
2.
3.
4.
5.
6.
7.
Place a piece of screen mesh
over the top of a cup
Hold it tight with a rubber band
Fill the cup with water
(just pour through the mesh)
Place a card on top and turn
upside-down
Remove the card by sliding it
Can you get a toothpick into the jar while it is upside-down?
Without any water coming out?
What happens when you poke a toothpick though the mesh?
How many drops of water
can a 10c coin hold?
Make a prediction
Add drops one at a time
using a pipette
What happens when it is too
“full”?
7) Plate of Pepper
1.
1.
Float a paperclip on the
surface of a cup of water
Take a cotton-swab and dip
one end in soap
Place the non-soapy end of
the swab in the cup (don’t
touch the paper clip)
What happens?
Place the soapy end of the swab in the cup (don’t touch the
paper clip) What happens?
2.
3.
4.
5.
Fill a plate with
water
Sprinkle
pepper evenly
all over the
water
Get a small
drop of soap on the end of your finger
Slowly touch your finger to the water right in the middle
What happens? Why?
8) Bubble Building
1.
2.
3.
4.
5.
6.
7.
Place just water
into a bowl
Use a straw to
blow bubbles
What type of
structures can you
form?
Add some soap and try again
Can you make bubbles inside a bubble?
What happens if you make one bubble bigger?
Does soap help or hurt surface tension?