Chlorine (Cl) is a highly reactive, yellow-green gas at room temperature, belonging to the halogen group in the periodic table. It has a distinctive, strong odor and is known for its powerful disinfectant properties.

Physical Characteristics:

Atomic Number: 17
Atomic Weight: 35.453 u
Density: 3.2 g/L at 0°C and 1 atm (gas), around 1.56 g/cm³ in its liquid form at -34°C
Melting Point: -101.5°C (-150.7°F)
Boiling Point: -34.04°C (-29.27°F)

Applications:

Water Treatment: Chlorine is widely used for disinfecting drinking water and swimming pools, effectively killing bacteria and other pathogens to prevent waterborne diseases.
Bleaching Agent: In the form of chlorine bleach (sodium hypochlorite), it is used extensively in the textile industry, paper production, and household cleaning products to remove stains and whiten fabrics.
Chemical Industry: Chlorine is a key reactant in the production of various chemicals, including solvents, pesticides, and plastics like PVC (polyvinyl chloride).
Pharmaceuticals: It plays a crucial role in synthesizing a wide range of pharmaceuticals and medical products, contributing to public health and medicine.

Compounds:

Sodium Hypochlorite (NaClO): A primary ingredient in bleach and disinfectants, used for cleaning and water treatment.
Hydrochloric Acid (HCl): Produced by combining chlorine with hydrogen, this strong acid is utilized in industrial processes, including metal cleaning, pH regulation, and food processing.
Chlorofluorocarbons (CFCs): Although their use is now heavily restricted due to their harmful effect on the ozone layer, CFCs were once widely used as refrigerants and propellants.
Polyvinyl Chloride (PVC): Chlorine is a critical component in manufacturing PVC, a versatile plastic used in construction, piping, and medical devices.

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