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CHEMISTRY NOTES FOR FORM THREE. BY ANNAMMA ABRAHAM SUPERVISED BY DR. MBANGWANA MOSES. HALOGENS. Meaning: Salt producers Position in periodic table : Group seven Members in halogen family: -F (fluorine)
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CHEMISTRY NOTESFOR FORM THREE BY ANNAMMA ABRAHAM SUPERVISED BY DR. MBANGWANA MOSES
HALOGENS Meaning: Salt producers Position in periodic table: Group seven Members in halogen family: -F (fluorine) - Cl ( Chlorine) - Br ( Bromine) - I ( Iodine)
ELECTRONIC STRUCTURE • F9= 2, 7 • Cl17 = 2, 8, 7 • Br35 = 2, 8, 18, 7 • I53 = 2, 8, 18, 18, 7 All have 7 electrons in the outermost shell
PROPERTIES OF HALOGENS • All are colored and non- metallic • F9= 2, 7 (Pale green gas) • Cl17 = 2, 8, 7( Greenish yellow gas) • Br35 = 2, 8, 18, 7( Reddish brown liquid) • I53 = 2, 8, 18, 18, 7( Black solid)
REACTIVITY OF HALOGENS Reactivities of halogens decreases down in the group Example: From F to I ( Fluorine to Iodine) Cl2 displaces Br2 from a solution of Bromide Cl2 + 2KBr 2KCl + Br2(Reddish Brown colour) Br2 will displace I2 from the solution of Iodide Br2 + 2KI 2KBr + I2( Black) Fluorine is the most reactive element in the group and Iodine is the least reactive.