Chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6, making it part of the d-block transition metals. Chromium is a steely-grey, lustrous, hard and brittle transition metal. It is a member of the periodic table and is often found in nature together with iron and nickel. Chromium is highly valued for its high corrosion resistance and hardness, though it is often used to give objects a shiny, attractive outer surface.
Composition
Chromium is an element made up of three naturally occurring isotopes. The most common is chromium-52, which makes up 83.8 percent of chromium found in nature. Chromium-48 and chromium-54 each make up 9 percent of natural chromium. Chromium has a 43.4 percent abundance in the Earth’s crust and is the eleventh most common element in the universe.
Characteristics
Chromium has a shiny grey-white appearance when made into a metal and resists tarnishing. The metal also has a high melting point of 1907 °C and a boiling point of 2671 °C, making it a suitable material for use in metal alloys. Its high strength and hardness make it useful for engineering applications and for industrial use. When chromium metal is exposed to air, it forms an oxide layer on its surface, creating a protective barrier that prevents further corrosion. This oxidation also makes chromium metal reflective and lends it its characteristic silvery-white color.
Uses
Chromium is mainly used in the production of stainless steel, as well as in plating and alloying. It is also found in paints and in leather tanning processes. Chromium also has important uses in catalysts and biocides, and is widely used in the chemical and pharmaceutical industries. In addition, chromium is used in the manufacturing of synthetic rubbers and polymers, as well as in ceramics. Due to its corrosion resistance, chromium is also widely used in automotive and aerospace engineering applications. Chromium compounds are also used in coal gasification processes as well as in the production of a wide range of dyes and pigments.
Health Risks
Chromium in its chromium (VI) form is a known carcinogen if ingested, inhaled or absorbed through the skin. As such, it is subject to strict regulations about its use and storage. Many industries are now adopting measures to reduce their use and release of chromium into the environment. However, the main sources of chromium exposure are inhalation and ingestion. Long-term exposure to chromium can cause asthma and other pulmonary disorders, as well as increased risk of developing cancer.
Conclusion
Chromium is an important and widely-used chemical element. It has a number of valuable and important uses in industrial, chemical and pharmaceutical processes. Despite its applications, it is crucial that any use of chromium is done with caution and appropriate safety measures in place due to its known carcinogenic properties.
