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BONDS. A force that holds atoms together in a molecule. Types of Bonds. There are several types of chemical bonds. We will focus our attention on the 2 main types of bonds. Ionic bonds Covalent bonds. Why do bonds form?.
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BONDS A force that holds atoms together in a molecule.
Types of Bonds • There are several types of chemical bonds. We will focus our attention on the 2 main types of bonds. • Ionic bonds • Covalent bonds
Why do bonds form? • The most stable arrangement of electrons in an atom is a full outer orbit. • This means 8 electrons for almost all atoms. (Octet rule) • The only exceptions are H and He which only need 2 electrons to have a full outer orbit. • This is why Noble Gases rarely form compounds.
In order to fill this outer orbit, atoms will give, take, or even share electrons.
Electrons are transferred from one atom to another. Contains one metal & one nonmetal. Only 1 formula is possible between 2 elements. NaCl is possible but NaCl2 is not. Pairs of electrons are shared between 2 atoms. Contains 2 nonmetals or hydrogen and a nonmetal. More than 1 formula is possible between 2 elements. CO and CO2 IONIC vs. COVALENT
Covalent Bonds Both molecules are made up of carbon and hydrogen CH4 C2H6
Find the formula for the compound by using the criss-cross method. Naming – The metal name is always first. The nonmetal name is last with the ending changed to -ide. Find the formula using electron dot structures. Naming – Using prefixes. Examples carbon monoxide carbon dioxide IONIC vs. COVALENT
Prefixes • One mono- • Two di- • Three tri- • Four tetra- • Five penta- • Six hexa- • Seven hepta- • Eight octo- • Nine nono- • Ten deca-