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The halogen elements show great resemblances to one another in their general chemical behaviour and in the properties of their compounds with other elements.
The hydrogen bonds between hydrogen fluoride molecules are considerably weaker (7 kilocalories per mole) than those within the molecules (135 kilocalories per mole), yet they are retained to a great extent in the .
Similar hydrogen bonding exists in the other hydrogen halides, but it is considerably weaker.
Fluorides are usually more stable than the corresponding chlorides, bromides, or iodides.