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  • Chemistry, ES Revision Notes


    The Dead Sea

    • Extremely high water density

      • Salt is 350gdm-1

      • Normal is 40gdm-1

    • 400m below sea level

    • Huge evaporating basin

    • High proportion of bromide salts

    • Major source of minerals

    • Mainly group 7 ions

    The p-block, Group 7

    • Halogens are group 7 elements

    • All have 7 electrons in outer shell

    • Most reactive group of non-metals

    • Not found naturally in elemental form

    • Abundance decreases down group

    • All occur as diatomic molecules

    Halogen bonding in compounds

    In compounds, there several ways by which a halogen can achieve stability:

    • Gaining an electron from a metal atom, forming a halide ion in an ionic compound

    • Sharing an electron with a non-metal atom in a covalently bonded compound

    Physical Properties of Halogens

    A table to show the physical properties of some halogens