CHEMICAL BONDING

Elements can be combined in different ways: Physically Form mixtures Ex. Air Chemically Form compounds Ex. Water

Compounds Elements are combined in definite proportions Represented by formulas Show the kind and number of each atom C6H12O6 6 carbon atoms 12 hydrogen atoms 6 oxygen atoms

Atoms form bonds based on their outermost electrons Valence electrons determine reactivity 2-8-8 rule Atoms whose valence shells are complete are stable/non-reactive

Types of Bonds: Ionic Covalent Hydrogen

Ionic Bonding Combines metal and non-metal Electrons are transferred from one atom to another Result in charge atoms called ions Attraction between + and – keeps bond  

Ionic Bonding Example: Na + Cl  Na+ Cl- sodium metal chlorine gas                +                                           sodium metal chlorine gas table salt

One atom gives up an electron, one takes on an electron Sodium has 1 electron in its valence, chlorine has 7 electrons in its valence Sodium + Chlorine

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Covalent Bonds Form between 2 non-metals Electrons are shared http://www.visionlearning.com/library/flash_viewer.php?oid=1348&mid=55