Calcium is an essential element, symbolized as Ca with an atomic number of 20, known for its pivotal role in both biological and industrial domains. This dull gray, soft metal is highly reactive, especially with water, and forms compounds like calcium hydroxide and hydrogen gas upon contact. In nature, calcium is abundant, primarily found in minerals such as limestone, gypsum, and fluorite
Biologically, it is crucial for the structural integrity of bones and teeth, muscle contraction, blood clotting, and cellular signaling. Industrially, calcium is indispensable in the production of cement, steel, and various chemicals. It is also used in agriculture to neutralize soil acidity and as a dietary supplement in the food industry.
Chemical Properties:
- Reactivity: Highly reactive, especially with water, forming calcium hydroxide and hydrogen gas. It also reacts with oxygen and halogens.
- Crystal Structure: Face-centered cubic (fcc)
- Electronegativity: 1.00 (Pauling scale)
Occurrence and Production:
- Abundance: Fifth most abundant element in the Earth's crust, making up about 3.6% by weight.
- Natural Sources: Found primarily in minerals such as limestone (calcium carbonate, CaCO₃), gypsum (calcium sulfate, CaSO₄·2H₂O), and fluorite (calcium fluoride, CaF₂).
Uses:
- Construction: Used in cement and concrete production as calcium carbonate and calcium oxide.
- Metallurgy: Acts as a reducing agent in the extraction of metals like thorium, uranium, and zirconium.
- Chemical Industry: Utilized in the production of calcium compounds such as calcium chloride, calcium nitrate, and calcium sulfate.
- Agriculture: Employed in the form of lime to neutralize acidic soils and improve soil structure..
- Used in fertilizers to supply calcium to plants..
Safety and Handling:
- Reacts vigorously with water, releasing hydrogen gas, which can be explosive in certain conditions.
- Should be stored in a dry, airtight container to prevent reactions with moisture.
- Environmental Impact: Bromine compounds can have significant environmental effects, particularly related to the depletion of ozone in the stratosphere.
