Bonding and Nomenclature Ms. Oster - Physical Science

What is a chemical bond? Chemical Bond: An attraction between atoms that allows for the formation of molecules (2 or more atoms together). Two main types: Ionic Bond Covalent Bond

Ionic Bonds REMEMBER: An ion is a charged atom. So… ionic bonds form between charged atoms. Ionic bonds form between a metal and a non-metal. Metals take on positive charges by losing valence electrons. Non-metals take on negative charges by gaining electrons

Ionic Bonds Cont... Valence electrons - Metal donates - Nonmetal accepts - charges like magnets

Ionic Bond Nomenclature (naming) Always write the metal first and non-metal second Ex: NaCl Say the metal name first and the non-metal second with an “-ide” and the end Ex: Sodium Chloride, Magnesium Oxide Number charges become subscripts on the other atom Ex: Mg2+ and Cl1- → Mg1Cl2 → MgCl2

Practice makes Perfect Element #1 Element #2 Compound Compound Name Dot Diagram Na Cl NaCl Sodium Chloride Na+ Cl - Mg I K Br

Covalent Bonds The prefix “Co-” means “together” (cooperate, coordinate) So atoms in a covalent bond, work together! Covalent bonds form between a non-metal and another non-metal The atoms share their electrons in order to have a full outer shell.

Covalent Bonds Continued... share electrons, full outer shell

Covalent Bond Nomenclature (Naming) Say the elements in group numerical order. Exception: when the compound contains oxygen and a halogen, the halogen is first. If in same group: higher period comes first. Include prefixes in front of each element name to represent how many atoms there are. Same as ionic bond naming with “-ide” at the end of the second element name Charges become subscripts on the other atom Notice no mono in front of carbon Examples: H20 = dihydrogen monoxide; CO2 = carbon dioxide

Covalent Bond Nomenclature Continued... You need to memorize these prefixes! Make flash cards!

Practice Makes Perfect! Element #1 Element #2 Compound Compound Name Dot Diagram Cl Cl2 Chlorine Cl Cl H O C