Ionic and Covalent bonding

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Ionic and Covalent bonding
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Bonds

• All atoms are trying to get enough electrons so
  that their valence shell is full.
• This is referred to as the OCTET RULE or
• Atoms of elements will lose, gain, or share
  electrons in such a way that their electron
  configurations contain eight valence electrons.
• Elements can do this in several ways.

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Ionic bonds

• An ionic bond is the result of attraction between
  positive and negative ions.
• Ionic compounds come together in a way that
  balances out the charges on the ions.
• Scientists write compounds a specific way by a
  chemical formula.
• The ions are both represented by their atomic
  symbol, and the number of atoms of each is
  represented with a subscript number.

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For Example

• A ionic compound containing a magnesium ion with
  a charge of 2 bonds with chlorine.
• Chlorine has a 1- charge so 2 chlorine atoms are
  needed to balance out the 2 charge.
• The chemical formula would be MgCl2.

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Naming ionic compounds

• The name of the positive ion goes first followed
  by the name of the negative ion.
• Of the negative ion is a single element then the
  end of its name changes to ide.
• NaCl sodium chloride
• MgCl2 magnesium chloride

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• If the ionic compound is polyatomic the name
  usually ends in ate, or ite
• NH4NO3- ammonium nitrate

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..

• See if you can figure out what the chemical
  formula for a compound containing Sodium (Na) and
  Chloride (Cl) would be.
• How about a compound of Calcium (Ca) and Carbon
  (C ) and oxygen (O).

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Check for understanding

• Write the chemical formulas for the following
  compounds.
• Sodium bromide
• Lithium oxide
• Magnesuim sulfide
• Aluminum fluoride
• Potassium nitrate
• Ammonium chloride

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Properties of ionic compounds

• Hard, brittle crystals that have high melting
  points.
• When dissolved in water or melted they conduct
  electricity.

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Covalent bonds