Water molecules (part #1)/ Atoms (part #5)

Hi guys in this post we are going to talk about Meniscus’s and surface tension.

So first let’s talk about meniscus’s. There are two types of meniscus’s. 1 there is a concave meniscus. And 2 there is a convex meniscus.

In this drawing I drew a concave meniscus and a convex meniscus

So have you ever looked at a glass of water and thought that the surface of the water was flat? Actually it is “dented” downward. Because it is attracted to the glass more then it’s self. It is called a concave meniscus.

In this drawing I am showing you the surface of water is NOT flat and that it is actually “dented” downward.

In this drawing I drew a tiny concave meniscus on a molecular basis. And the silicons bonded to the 4 oxygens each are glass molecules.

Mercury is one of the elements that does a convex meniscus because it is attracted to it’s self more then the glass.

In this drawing I drew Mercury doing a convex meniscus

A convex meniscus is the opposite of a concave meniscus.

Now let’s talk about surface tension.

So if we had a bunch of water molecules and we look at one of the middle water molecules it is being pulled in so many different ways. North or south or east or west and many more ways! Because some of the other water molecules are hydrogen bonding with that water molecule which is why it is being pulled in so many different ways.

In this drawing I drew a bunch of water molecules and I am focusing on one of the middle water molecules and I am showing hydrogen bonds pulling on that water molecule.

But if you look at one of the water molecules on the surface, half of it is being surrounded by water molecules and half of it is being surrounded by air. And because of that, only half of it is being pulled by hydrogen bonds from other water molecules. The other half, which is surrounded by air, does not have any force pulling on it because the molecules in the air don’t bond with the water molecules. And that let’s the water molecules on the surface get closer together. And that is surface tension.

In this drawing I drew a lot of water molecules and I am focusing on one of the surface water molecules and I am showing half of it is being pulled by hydrogen bonds. And I’m also showing you that the surface molecules are able
to get closer together.

And because of that there are some animals that can walk on the surface of water!

In this drawing I drew a pond with a water snake and a spider on the surface of the water ( by the way I have seen a water snake before).

And if you get a tub of water and you fill it even higher then the rim, it will form a “bump” over the rim, because the water is attracted to it’s self more then the surrounding air.

In this drawing I drew a tub of water and I drew the “bump” of water over the rim.

I wrote this from memory from what I learned in khan Academy

Now it is time for us to say goodbye and you will see what I am going to talk about in the next post. By 😊👋