Higher surface tension and, in most cases, higher viscosity result from stronger forces between particles. Most notably, mercury has an extremely high surface tension yet is no more viscous than cold water. This shows that the force binding its atoms together is very strong.
Mercury's strong attractive force results from its shape. The electron cloud surrounding each atom forms a spherical shell that can only be penetrated by particles with similar shapes. Thus, if mercury were flat, it could not retain its current form.
This same property makes it difficult to dissolve mercury in other substances. Even when exposed to heat or chemicals for a long time, it will not dissolve. This is why tests must be done in a glass container with acid added. If the container is made of metal, even aluminum, the acid will react with the metal and become ineffective. If you use plastic, there is a chance that it will release toxic compounds into the solution. It is best to use glass or ceramic containers for these experiments.
As mentioned, mercury has high surface tension which means that it likes to stay away from other substances. This means that it does not mix well with other materials in your experiment. If you put mercury in a tube and let it dry, you will likely find chunks of mercury at the bottom of the tube because it did not mix well with the plastic.
The surface tension of mercury is greater than that of water. This may be shown by comparing a drop of water to a drop of Mercury. The higher the surface tension of the liquid, the higher the liquid bead will bend. For example, gold is used in jewelry because it has a high surface tension so it does not wet other materials like silver or copper.
Surface tension was first discovered by Italian scientist Angelo Giuseppe Marchetti in 1748. He called it "estrema attrazione" which means extreme attraction.
Before modern science came about, people believed that elements with similar properties derived from the same source had a special connection with one another. For example, if some mercury was found near fish then it was assumed that both were affected by the ocean. Scientists today know that this is not true but it served as a guide for scientists to look for similarities between elements that were found at the time. They would compare their findings to what was known about other elements and try to make sense of what they saw. This is how Angelo Giuseppe Marchetti made his discovery. He noticed that the metal he was working with had some properties in common with gold and therefore tried other metals to see if they had any connections as well. It turns out that they all have something in common - they're all heavy!
The cohesive forces between mercury atoms, on the other hand, are substantially stronger than the adhesive forces between mercury and glass. Surface Tension, Viscosity, and Capillary Action (7.1)
Why does mercury bead up so easily into spheres? Because of its strong metallic bond, mercury has extraordinarily high cohesion and surface tension. Because of its enormous dispersion forces, mercury has extraordinarily high cohesion and surface tension. Because mercury is a liquid, it cannot form metallic connections. It must be in a solid or vapor state for there to be connection between atoms. When mercury is in a solid state it can form alloys with other elements including gold. But because its cohesive energy is so high, it does not mix with other substances except in alloys.
Beading up mercury is simple if you have access to mercury itself. If you buy mercury thermometers, they usually contain enough mercury for many experiments. You should never try this procedure with any other material other than mercury!
The first thing you need to know about beading mercury is that you cannot use heat to do it. The only way to melt mercury is with an electric current - which means using a battery as we will see below. Beading mercury is easy if you have access to batteries too. Once you have collected enough mercury beads, you can make some interesting projects such as musical instruments and toys.
You might wonder why you would want to bead up mercury. The most common use for this activity is in science class experiments. Science teachers often use laboratory exercises to help their students understand concepts related to chemistry, physics, biology, and technology.
Mercury is a non-wetting liquid because the cohesion forces inside the droplets are stronger than the adhesive forces between the drops and the surface. It does not moisten most surfaces due to its high surface tension. However, some materials do absorb moisture from the atmosphere when exposed to mercury vapor. These include gelatin film and certain types of wood, which will eventually rot if they retain moisture.
You should avoid exposing items made of gelatin to mercury because it will slowly dissolve the gelatin and release the mercury into the environment. Items made of wood can absorb moisture and eventually decay if not treated properly either by heating or burning. Mercury is very toxic to humans and animals. It is also very harmful to our environment. Do not handle mercury without proper protection or waste management procedures in place. The U.S. government does not allow the disposal of mercury into regular trash bins!
People who work with mercury every day should use protective equipment such as gloves, goggles, and aprons. The American Medical Association recommends that people avoid exposure to mercury vapor because even low levels of exposure may cause neurological problems.
In conclusion, mercury is a dangerous chemical that should be used under supervision by trained personnel. It has no color or smell and it should not be poured into garbage containers. All forms of mercury are toxic and should not be dumped into regular trash bins!
Because water wets the surface and crawls up the wall of a tube containing liquid water, the surface (meniscus) has a concave form. The cohesive forces inside the droplets are stronger than the adhesive forces between the drops and the glass, hence mercury does not wet glass. It is also worth mentioning that the density of mercury is about 11/2 times that of water so there is less chance of two drops clashing together.
Mercury's surface tension is very low. This means that it will easily spread out into a thin layer, which allows it to cover large areas of surface quickly; this is why it is used as an electrical conductor in telephone cables.
But its cohesion energy is high, so it won't spread out unless forced to. This means that it doesn't slide around as water does, but rather remains in one place. If you put two drops of mercury on top of each other they will merge slowly until all the energy levels are equal. At this point there is no more force acting to keep them separate so they will stay merged even if you shake the bottle up or down. This is why mercury does not mix with water-based substances - it would be like trying to blend oil and water. As soon as you stop shaking the bottle the mercury will float back up to the top because now the energy levels are unequal again.
Finally, note that mercury is toxic.