Why is water rounded in small quantities like in a bubble, but flat lin larger quantities?

Question

In a glass, water appears perfectly flat, but in a spoon or on the head of a nail it appears to be rounded. Can anyone explain this?

Answer 1

look up adhesion and cohesion (properties of water)

Answer 2

Surface tension vs. gravity.  In small quantities the surface tension is sufficent to pull the water up and in.  In larger quantities this surface tension is still present, but less obvious.  Here's something to try,- fill up a glass with water, and look carefully at the place where the glass and the water meet.  As long as there isn't any soap in in the glass (which destroys surface tension), you'll see a little curve there.  That is called the meniscus and is caused by the surface tension of the water.  If you have a drop of water on the counter, put a little bit of soap on your finger and just barely touch it.  You'll see the drop flatten out as the soap attacks the surface tension.

Answer 3

In a droplet, the suface tension forces tend the molecules to hold on to itself due to cohessive action. In a glass,  the molecules on the top layer try to stretch out to hold on to the walls of the glass due to surface tension.  That is why, when the bubbles come out from the bottom of the glass, the adhessive property between water and air molecules hold on to keep it as bubble.