Ionic and Covalent Bonds

Two or more elements chemically combined. Compound

 called an ionic compound because it is made up of negative and positive ions that have resulted from the transfer of electrons from a metal to a non-metal. Ionic Compounds

 Ions in ionic compounds are held together by the electrostatic force between oppositely charged bodies. In other words, positive and negative ions attract. Ionic Compounds

For example: Sodium (Na) wants to lose ____ electron). Chlorine (Cl) wants to gain ____ electron). Ionic Compounds

Calcium needs to lose ____ electrons, and fluorine needs to gain ____ Calcium Fluoride

What happens? Calcium Fluoride

What happens? Calcium Fluoride

 In the chemical formula the symbols of elements are written with a subscript which indicates how many of that element are present in the compound  only numbers above one are written Chemical Formulas and Composition of Compounds

 Formula for sodium chloride =  Formula for calcium fluoride = Chemical Formulas and Composition of Compounds NaCl CaF 2

 Ionic compounds are called electrolytes.  Electrolytes are substances that when dissolved in water, conduct electricity. Electrolytes

 form when non-metals combine with non-metals  non-electrolytes because they form solutions that do NOT conduct electricity. Covalent/Molecular Compounds

 Valence electrons are shared between atoms to fill the outer shell Covalent/Molecular Compounds

pg. 191 #1, 2 (Lewis diagram instead), 3, 4, 6, 7 pg. 195 #1, 2, 6, 7, 9 Homework