Ch.5, Section 2

What happens when I rub a balloon and then place it on the wall? When I rub the balloon, Electrons are transferred to the surface of the balloon The balloon becomes negatively charged The negatively charged balloon is now attracted to the more positively charged wall A similar concept is displayed in Chemical Ionic Bonds

Atoms tend to react in a way that would lead them to have 8 valence electrons Elements that do not have 8 Valence electrons tend to react. When the elements react bonds are formed

Transition Metals 1-3 valence e-

Ionic Covalent Metallic

Ion : an atom or group of atoms that have an electric charge When an atom loses an electron, it becomes a positive ion When an atom gains an electron, it becomes a negative ion

Polyatomic ion : An ion that is made up of several atoms

Because oppositely charges particles attract, the positive Na + ion and negative F - ion attract each other This forms an Ionic Bond

Bonds that are formed by transfer of electrons from one element to the other. Each element will have 8 valence electrons after the transfer of electrons. Formed between Metals and non-metals Ionic Bonds form as the result of the attraction of positive and negative ions

When ionic compounds form, they come together to balance the charges on the ion. The Chemical Formula reflects this balance Example: Magnesium Chloride 2 Chlorine ions (each with -1 charge) are needed to balance the +2 Magnesium Ion The Formula is: Note: If no subscript, then 1 is implied

For an ionic compound: The name of the positive ion comes first, followed by the negative ion Positive Ion name: The name of the metal (or polyatomic ion) Negative Ion Name: ends in -ide if only one element ends in -ate or –ite if polyatomic

Positive Ion + Negative Ion Negative Ion Name: ends in -ide if only one element ends in -ate or –ite if polyatomic Examples: NaClSodium Choride K 2 SPotasium Sulfide CaCO 3 Calcium Carbonate

Hard, brittle crystals High Melting Point When dissolved in water, conduct electricity

Ionic bonds are strong They transfer electrons Making + and - ions Metals and nonmetals get along Their melting point is high They conduct electricity – oh my Tiny crystals they will make Like pretty snowflakes