Mercury is both a liquid and a metal at ambient temperature (due to its extremely low melting point of -39C). However, under the pressure of thousands of feet of water it will solidify.
It is this property that makes mercury useful as a global medium for communication because you can float messages down rivers or stream beds. As soon as they reach the surface, however, these messages would be lost since mercury freezes at that temperature.
That is why ancient civilizations used containers made out of materials such as gold, silver, and copper when sending messages over large distances. These materials are much better at withstanding temperatures than plain old wood or stone.
Today, computers use electricity to communicate information via transistors which are switched on and off at high speed using electric signals. The problem is, electric signals decay over distance so these messages too would be lost before they could get very far.
The only solution is to use some kind of energy source which does not decay over distance. Mercury fits this description since it is both a liquid and a metal at room temperature. Messages sent in the form of radio waves might be able to travel longer distances but they require a clear line of sight and even then they would still be vulnerable to interference from other radio transmissions.
Mercury has a melting point of -38.9 degrees Celsius, a boiling point of 356.7 degrees Celsius, and is the only metal that remains liquid at ambient temperature. Droplets of liquid mercury are gleaming and silver-white, with a strong surface tension that makes them look spherical when placed on flat surfaces.
It is these physical properties that make mercury so useful in scientific experiments. The hardness of mercury is slightly greater than that of gold or platinum, but less than diamond. Its density is 11.3 grams per cubic centimeter.
The interaction of light with matter is different for different elements. This fact can be used to identify an element by its spectral characteristics. For example, the color of sunlight through glass containing silver is blue-green because this is the color of light after it has passed through air (which contains oxygen) and water (which contains many molecules of hydroxyl, or OH-, which have a green color). The color of sunlight through glass containing mercury is black because this is the color of light that has no longer any reflection within the glass itself.
You may have heard that mercury is toxic. This is true but only if you swallow it or inhale it in small amounts over time. If you touch it or come into contact with it then you should wash your hands immediately to prevent skin irritation. Eating food contaminated with mercury doesn't seem to pose any risk to humans.
Mercury is a peculiar material in that it is a metal that is liquid at ambient temperature. This is feasible since liquid nitrogen is significantly colder than -38.83 degrees Celsius, while mercury freezes solid at -38.83 degrees Celsius...
...although this does not mean that it is safe to handle! The key point is that the ratio of mercury's heat capacity to its volume increases as the third power of decreasing temperature. This means that if you could bring mercury down to -88.44 degrees Celsius, then it would be almost completely frozen yet still retain most of its weight.
However, this cannot be done with liquid mercury because the heat capacity per unit volume is so high that even a small amount of water or other molecules will melt it. For example, a cube of liquid mercury has a surface area of 1 square centimeter. This means that it will absorb approximately 100 joules of energy in any given second from its surroundings. If it was put into a vacuum and cooled to -88.44 degrees Celsius, then it would freeze instantly.
This shows that although liquid mercury can be frozen, it must be frozen from below 0 degrees Celsius and not from above this value.
Mercury Consolidation Because of its weak atomic bonds, mercury is a liquid at room temperature. However, under high pressure it can form crystals. The melting point of mercury is 382.15 degrees Celsius (737.79 degrees Fahrenheit). At 500 degrees Celsius (932 degrees Fahrenheit), mercury becomes a gas.
Behavior of Mercury When it reaches 500 degrees Celsius, the mercury will evaporate immediately because there is no longer any surface for it to condense into droplets. Before it reaches this temperature, though, it first becomes a gaseous substance. This means that it is not only vaporizing but also expanding rapidly due to thermal energy. The heat from the burning candle will be transmitted to the surrounding air, causing the atmosphere to expand and the distance between the candle and the mirror to decrease. As the distance decreases, more light is reflected back toward the observer, who sees an increase in brightness. After about 10 minutes, the candle flame will be almost invisible as the increased distance between it and the mirror prevents any light from being reflected back toward Earth.
Precautions Against Injury When working with hot substances, such as candles and mercury, precautions should be taken to avoid injury. All workers should use caution not to touch hot surfaces when performing work on hot materials.
Mercury is a chemical element, and it is the only common metal that is liquid at room temperature. At room temperature, mercury metal is a volatile liquid with a noticeable vapor pressure. The density of mercury at 20 °C is 13.6 g/cm-3. Mercury is a liquid metallic element that has a wide range of uses. It can be found in many products that we use every day without knowing it: thermometers, fluorescent light bulbs, barometers, and even cell phones can contain small amounts of this important element.
Even though it is a heavy element, mercury has a very low density. This means that it takes up a large amount of space compared to its weight. Other elements with similar properties include tin (density 1.81 g/cm-3) and lead (density 11.33 g/cm-3). Elements with higher densities than mercury include uranium (density 22.70 g/cm-3), platinum (diameter 38.9 mm) and gold (density 11.34 g/cm-3).
The density of mercury is so low that one cubic centimeter of gas will fill one quarter of the volume of one cubic meter of mercury. This is called "mercury's rare property".
Many things can affect the density of an element including its number of electrons, its shape, and its interaction with other substances.
Physical Characteristics At normal temperature, mercury is a silvery-white, gleaming metal.
|Melting point, °C||−38.89|
|Boiling point at 101.3 kPa, °C||357.3|
|Density at 0°C, g/cm3||13.5956|
At room temperature, mercury (element #80, symbol Hg) is a thick, heavy, silvery metallic element. Only three additional elements are liquid at or slightly above room temperature (bromine, cesium, and gallium). Pure mercury is most commonly found in association with the ore material cinnabar....
Mineral forms of mercury are rare. The most common form is mercuric chloride, which is used as a pesticide and preservative in vaccines. Other less common forms include elemental mercury, calomel (mercurous chloride), and stannomalerucuim (a tin-silver alloy). Calomel has been used as a treatment for chronic constipation and for problems with the urinary system. Stannomalerucuim was formerly used as a thermometer material because of its capacity to change color when it reaches different temperatures.
Elemental mercury is the name given to pure mercury that is not bound up with other substances. It can be in a solid state or gas state. If it is in a gaseous state, it is called hydrargyrum; if it is in a liquid state, it is called quicksilver. Elemental mercury is extremely toxic if it comes into contact with skin or if it is inhaled. It is very reactive and will combine with other chemicals to create new compounds that are also highly toxic.