merkuuri

Merkuuri, also known as quicksilver, is a chemical element with the symbol Hg (from the Latin *hydrargyrum*, meaning "liquid silver") and atomic number 80. It is a heavy, silvery d-block transition metal that is liquid at room temperature, making it one of only two such elements alongside bromine. Merkuuri is highly toxic and poses significant health risks through inhalation, ingestion, or skin contact, requiring careful handling in industrial and laboratory settings.

In its pure form, merkuuri is a dense, shiny metal with a silvery appearance and a slight bluish tint. It exhibits unique properties, such as high thermal and electrical conductivity, though its liquid state limits practical applications in electronics. Historically, merkuuri has been used in thermometers, barometers, and fluorescent lamps due to its low freezing point (−38.83 °C or −37.89 °F) and high vapor pressure. However, its toxicity has led to widespread restrictions on its use in consumer products.

The element occurs naturally in cinnabar (mercury(II) sulfide), a bright red mineral that has been mined since ancient times. Extraction involves heating cinnabar to release merkuuri vapor, which is then condensed. Industrial applications historically included fungicides, pesticides, and dental amalgams, though these uses have declined due to environmental and health concerns. Merkuuri pollution, particularly from mining and industrial discharge, has contaminated waterways and soil, affecting ecosystems and human health.

Biologically, merkuuri accumulates in living organisms through a process called biomagnification, becoming more concentrated at higher trophic levels. Exposure can lead to neurological damage, kidney failure, and developmental issues in children. International regulations, such as the Minamata Convention, aim to reduce merkuuri emissions and phase out its use in certain products. Despite its dangers, merkuuri remains important in specific scientific and medical applications, such as in some vaccines and laboratory equipment.