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Understanding the element
Chlorine (Cl) is chemical element 17. It belongs to the halogens, and its reference state at room temperature is a gas. Those basic facts are a useful starting point for its chemistry and applications.
Where do we encounter it?
In practice, it turns up most often in water treatment, PVC and chemical synthesis.
water treatmentPVCchemical synthesis
Standard atomic weight[35.446, 35.457]
What its position in the table tells us
Chlorine sits in period 3, group 17 and the P block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.
Worth remembering
Chlorine has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses
Chlorine has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses