Bellringer: Copy and Answer 1.What is an “ion”? 2.Why do ions form? 3.Ionic bonds are formed between oppositely-charged particles, positively- charged __________ and negatively- charged ______________. 4.Cations are usually ____________, while anions are ___________. (What types of elements?) 5.Name the following ionic compounds: Na 2 O, BeCl 2, NH 4 OH

The Covalent Bond Objectives: AHSGE Reading 4.3 Discern organizational patterns. 3.1 Utilizing electron configurations, Lewis dot structures, and orbital notations to write chemical formulas 6.1 Predicting ionic and covalent bond types Other AOD C.2.1 Describe types of covalent bonding between carbon atoms as single, double, or triple bonds.

Ionic bonds are formed by a transfer of electrons from __________ to ________. Covalent bonds are formed when electrons are shared by two or more atoms, rather than transferred from one to another. This sharing is done to give ALL the electrons a complete _________ of valence electrons. Covalent bonds USUALLY form between nonmetal atoms. What is a Covalent Bond?

Molecules Ionic bonds form ionic compounds: oxides and salts. Covalent bonds form molecules. Diatomic molecules: ???? Answer: 2-atom molecules Examples: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2 These elements exist in nature as diatomic molecules because they are more stable in that form

Formation of a Covalent Bond As 2 atoms approach each other, two forces become important: 1.Repulsive forces between their nuclei (protons) and between their electrons 2.Attractive forces between the nucleus (protons) of one atom and the electrons of the other atom Point of maximum attraction: As the atoms move closer to each other, the attraction b/t nucleus and electron increases until it is equal to the repulsive forces (the most stable arrangement!!! = bond length)

Types of Covalent Bonds 1.Single covalent bonds (sigma bonds): one shared pair of electrons –H 2 OR H-H –H 2 O OR H-O-H –NH 3 or NBr 3 or NCl 3 (WHY??) –CH 4 Lewis Dot structure diagrams on board (refer to Fig. 9-3, p. 243)

Types of Covalent Bonds(continued) 2.Double covalent bonds (1 sigma bond and 1 pi bond): 2 pairs of shared electrons –Example: O 2 3.Triple covalent bonds (1 sigma bond and 2 pi bonds): 3 pairs of shared electrons –Example: N 2 Lewis Dot structure diagrams and bond representations on board (refer to Fig. 9- 5, p. 245)