Midterm Review Chapter 5 & 6 Covalent and Ionic Bonding

Ions Octet Rule – to be stable atoms have to have 8 electrons in their outer energy level. (Exceptions H and He which only need 2) Atoms will form bonds in order to satisfy the octet rule Once atoms form bonds, their electron configurations mimic the noble gases or they have a psuedo -noble gas configuration

Ionic Bonds Ions – atoms gain or lose valence electrons. – This gives them a negative or positive charge – If an atom gains an electron it becomes negative – If an atom loses an electron it becomes positive

Cations vs Anions Cations – term for positive ions. They have lost one or more electron(s) Anions – term for negative ions. They have gained one or more electron(s).

Ionic Bonding Cations and Anions have opposite charges. The opposite charges attract each other This attraction is how ionic bonds form

Ionic Bonding Always from between a metal and a non- metal Metal is always the cation Non-metal is always the anion

Salts Are always ionic bonds Have crystal lattice structures Have high melting points

Naming Ionic Compounds Metal always comes first Metal stays the same. Example – Potassium and Iodine form an ionic bond The name of this compound would be potassium iodine

Covalent Bonds Form when two or more atoms share electrons Only forms between two non-metals

Lewis Dot Diagrams

Lewis Dot Diagrams are a visual representation of an atom’s valence electrons It is a chemical symbol surrounded by dots which represent the valence electrons