November 18, 2016
The theme of the fourth Science Friday was “Water”. We talked about the water molecule and hydrogen and oxygen atoms. As an introduction to the concept of buoyancy, students tested how various objects float or sink in water. Then the students moved on to surface tension experiments: they collected water droplets on a coin and floated a paperclip. Water absorption and water resistance was explored by drawing with crayons and painting over the drawing. (Little artists could not resist–pun intended–to paint some masterpieces in the process!) The students then moved on to the table where adult volunteer showed how looking at an object through water distorts what we see. We also observed how soap reduces water tension and mixed various liquids to discuss density.
Vocabulary: Atoms, Density, Surface Tension, Water Resistance, Water Absorption, Capillary Action, Optical Inversion
Watch at home:
Try This at Home:
- WATER TENSION a) Fill a bowl with water. Sprinkle pepper. Does it float? Now add a drop of dishwashing liquid. What happens? b) Fill a plate with milk. Add drops of several food coloring in the center. Now add a drop of dishwashing liquid in the middle. What happens?
- CAPILLARY ACTION Fill one short container with water. Color it with food coloring for fun. Put an empty container next to the first. Fold a piece of paper strip over the two containers, with each end inserted into corresponding container and touching the bottom. Leave for several hours. Watch how water climbed up the paper and collected in the empty container.