Why does stainless steel float when coated with wax?

[hcho88]

Properties of Matter (Fluids)
Why is it possible to float a wax-coated stainless steel needle on the surface of water?

 

[Daimou43]

I think that it's surface tension that's keeping up the needle, regardless if it is waxed or not.

As long as the needle isn't submerged in water, it should be able to float.

 

[K^2]

Clean steel will be pulled into the water.

It's about energy, really. Think of it this way, why does needle sink? Because that reduces needle's gravitational potential energy. But you also have to move some water particles out of the way. That may or may not require energy.

If you have two water molecules next to each other, they are 'connected' by a hydrogen bond. To move the two molecules apart, you need to invest some energy to break that bond. This is what gives rise to surface tension. When the needle moves down, it moves molecules apart. If no new bonds are formed, that energy has to be supplied by the needle.

A waxed needle forms no hydrogen bonds of its own with surrounding water molecules. That means, it requires energy for needle to become submerged, and it actually turns out to be greater than amount of available potential energy.

A clean needle, however, will form its own bonds with water molecules. Perhaps not as strong as before, but enough to offset the above, and make it advantageous for the needle to sink.

 

[hcho88]

Thank you.

 

[pmacias]

Stainless steel is a type of metal that is known for its high strength and durability. It is also known to be non-porous and resistant to corrosion. However, when it is coated with wax, its properties change, making it possible for it to float on the surface of water.

The reason for this is due to the properties of matter, specifically the properties of fluids. Fluids, such as water, have a property known as surface tension. This is the force that holds the molecules of a liquid together, creating a sort of "skin" on the surface of the liquid.

When the wax-coated stainless steel needle is placed on the surface of the water, the surface tension of the water creates a force that is strong enough to hold up the weight of the needle. This is possible because the wax coating on the needle creates a barrier between the water and the stainless steel, preventing the water from coming into direct contact with the metal.

Additionally, the shape and size of the needle also play a role in its ability to float. The needle is small and has a relatively large surface area, which allows it to distribute its weight evenly on the surface of the water. This, combined with the surface tension of the water, allows the needle to float on the surface.

In conclusion, the ability of stainless steel to float when coated with wax is due to the properties of matter, specifically the surface tension of fluids. The wax coating creates a barrier that allows the needle to sit on top of the water, while the surface tension of the water provides the necessary force to hold it up.