Mercúr

Mercúr is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly known as hydrargyrum. Mercúr is the only metallic element that is liquid at standard conditions for temperature and pressure. This unusual property has made it useful in various applications throughout history.

The element is a heavy, silvery-white metal. It has a relatively high density and a low surface tension, which causes it to form droplets rather than spreading out. Mercúr is a poor conductor of heat but a good conductor of electricity. It can alloy with many other metals, forming amalgams. These amalgams are often solid at room temperature.

Historically, mercúr has been used in thermometers, barometers, and sphygmomanometers due to its liquid state over a wide temperature range. It has also been employed in electrical switches, fluorescent lamps, and some dental amalgams. However, due to its toxicity, many of these uses have been phased out or significantly reduced in recent decades.

Mercúr is a toxic heavy metal, and exposure can cause serious health problems affecting the nervous system, kidneys, and lungs. It can enter the body through inhalation, ingestion, or skin absorption. Environmental contamination with mercúr is a concern, as it can bioaccumulate in food chains, particularly in fish. Consequently, regulations and efforts to reduce mercúr emissions and promote safe disposal are in place globally.