...as opposed to crystals which just sink to the bottom and diffuse. This is what I observed in one of our biology experiments (on diffusion) with dark green ink(ink from a pen actually).
2007-10-07 08:21:34 · 6 answers · asked by kim p 2 in Science & Mathematics ➔ Other - Science
As a few people have already posted here, surface tension is the correct answer.
Water molecules have a tendency to attract adjacent similar water molecules by generating inward forces in all directions. However, on the surface of the water where water molecules and air molecules are in contact, this attraction is concentrated sideways and downward where other water molecules exist.
When you place ink very gently on water, it will initially float. However, after some passage of time, the ink will sink in the water because it is actually more denser than water. But before it can sink, it must defeat the water's surface tension.
Ink can do this because it contains impurities that are time dependent. The impure molecules need a little time to penetrate and interact with the water molecules to break down the surface tension. It may take seconds or minutes, but a point will be reached where the weight of the ink becomes a stronger force than the surface tension forces and causes the ink to sink.
2007-10-07 08:51:18 · answer #1 · answered by Horatio 7 · 0⤊ 0⤋
Surface tension!
You can float a pin on water if you're gentle enough.
Add a drop of detergent or alcohol & see the difference.
2007-10-07 08:24:43 · answer #2 · answered by Robert S 7 · 0⤊ 0⤋
ink is lighter than the water
2007-10-07 08:23:38 · answer #3 · answered by moosee^^; 3 · 0⤊ 0⤋
density and surface tension
2007-10-07 08:24:31 · answer #4 · answered by relaxed 4 · 0⤊ 0⤋
surface tension
2007-10-07 08:24:56 · answer #5 · answered by zippy_dell 3 · 0⤊ 0⤋
because of their different densities
2007-10-07 08:23:40 · answer #6 · answered by Anonymous · 0⤊ 0⤋