What is mercury?
Mercury is a chemical element with the symbol Hg and atomic number 80. It is the only metal that is liquid at room temperature, looking like a shiny, silvery droplet. In the periodic table it belongs to the transition metals group.
Let's break it down
- State: Liquid metal (melts at -38.8 °C).
- Appearance: Shiny, silvery, and reflective.
- Atomic structure: 80 protons, 80 electrons, and about 122 neutrons.
- Properties: Conducts electricity, expands when heated, and forms alloys called amalgams when mixed with other metals.
- Safety note: Mercury vapor is toxic if inhaled, and the metal can accumulate in living organisms.
Why does it matter?
Mercury’s unique liquid state makes it useful for precise measurements and scientific instruments. It also helps us understand how metals behave under different conditions, and its environmental impact teaches us about pollution and health risks.
Where is it used?
- Thermometers and barometers (measuring temperature and pressure)
- Fluorescent lighting and some types of batteries
- Dental amalgams (fillings) - though use is decreasing
- Scientific equipment like spectrometers and vacuum pumps
- Gold and silver mining to extract those metals from ore
Good things about it
- Excellent conductor of heat and electricity, useful in many devices.
- Expands uniformly with temperature, providing accurate readings in thermometers.
- Forms strong alloys (amalgams) that can be useful in dentistry and industry.
- High density makes it ideal for weighing and balancing applications.
Not-so-good things
- Toxic: mercury vapor can damage the nervous system, kidneys, and lungs.
- Persists in the environment, accumulating in fish and entering the food chain.
- Handling requires special safety gear and proper disposal methods.
- Many countries are phasing out mercury‑based products because of health and ecological concerns.