Focus Question: • How do electrons behave in a covalent bond?
Methane gas – CH4 • Water – H2O • Sugar!!! – C6H12O6 • Propane – C3H8 • Octane – C8H18 How are covalent bonds used in daily life?
Covalent Bond: atoms share one or more electrons with each other to form the bond. • Forms between two nonmetals What is a covalent bond?
Which of these would form covalent bonds? • CH4 or NaCl • b. H2O or MgO Practice:
3 Levels of Covalent Bonding • Single bond: when 2 atoms share 2v.e. • Double bond: when 2 atoms share 4v.e. • Triple bond: when 2 atoms share 6 v.e. Bond Key = 2e- = 4e- = 6e-
Which level of covalent bonding is the strongest? Why? The strongest type of covalent bond is a ______________ bond because ___________________. One Minute Essay (OME)
Writing Covalent Molecules Steps 1. Add up the number of valence electrons. The total is the only thing important. Ex. 1: PCl3
Writing Covalent Molecules Steps 2. Pick the element to write in the middle. Usually Carbon (C) or the 1st element. Write the other elements around the central element. Ex. 1: PCl3 v.e. = 26
Writing Covalent Molecules Steps 3. Complete the octetof the atoms bonded to the central atom EXCEPT H and He – only need TWOv.e. Ex. 1: PCl3 v.e. = 26 Cl P Cl Cl
Writing Covalent Molecules Steps 4. Place any leftover electronon the central atom, even if doing so results in more than an octet. If there are not enough electrons to complete the octet of the central atom, try multiple bonds. Ex. 1: PCl3 v.e. = 26 Cl P Cl Cl
Practice: • Ex. 2: SiH4 • Ex. 3: HCl • Ex. 4: CClH3
Practice: Ex. 2: SiH4
Practice: Ex. 3: HCl
Practice: Ex. 4: CClH3
Summary How do electrons behave in a covalent bond? • In a covalent bond, electrons are _____________ between nonmetals.