4s-orbital is filled before the 3d sub-shell. However, 4s-electrons are lost before the 3d- electrons. Write the electronic configuration of 1)Fe 2)Fe 2+ 3)Mn 2+ 4)Co 2+ 5)Ag+

Module 2, L1-7 mini test on Friday 11 th Nov Quick 10 on redox reactions on Monday 14 th November

Ionic bonding L.O.:  Describe ionic bonding as the electrostatic attraction between oppositely charged ions.  Draw dot-and-cross diagrams for ionic compounds.  Describe structures with ionic bonding as giant ionic lattices.  Predict ionic charge from an element’s position in the Periodic Table.  State the formulae for the ions NO 3 – ; CO 3 2– ; SO 4 2– ; and NH 4 +.

How many electrons are there in the outer main levels of noble gases? Why are the called noble gases? Why are they unreactive?

Full outer main level => stability

How can sodium attain the electronic structure of a noble gas? How can a chlorine atom attain the electronic structure of a noble gas?

SODIUM CHLORIDE Cl SODIUM ATOM 2,8,1 Na CHLORINE ATOM 2,8,7

SODIUM CHLORIDE Cl SODIUM ION 2,8 Na CHLORIDE ION 2,8,8 both species now have ‘full’ outer shells; ie they have the electronic configuration of a noble gas +

SODIUM CHLORIDE Cl SODIUM ION 2,8 Na CHLORIDE ION 2,8,8 NaNa + + e¯ 2,8,1 2,8 ELECTRON TRANSFERRED Cl + e¯ Cl¯ 2,8,7 2,8,8 +

MAGNESIUM CHLORIDE Cl MAGNESIUM ATOM 2,8,2 Mg CHLORINE ATOMS 2,8,7 Cl

MAGNESIUM CHLORIDE Cl MAGNESIUM ION 2,8 Mg CHLORIDE IONS 2,8,8 Cl 2+

What type of elements are Na and Mg? What type of element is Cl?

 Ionic boding occurs between metals and non-metals  Electrons are transferred from metal atoms to non-metal atoms.  Positive and negative ions.

Cl - Chloride ion Na + Sodium ion A giant ionic lattice is a three-dimensional structure of oppositely charged ions, held together by strong ionic bonds.

GIANT IONIC CRYSTAL LATTICE Each Na + is surrounded by 6 Cl¯ (co-ordination number = 6) and each Cl¯ is surrounded by 6 Na + (co-ordination number = 6). Oppositely charged ions held in a regular 3-dimensional lattice by electrostatic attraction The arrangement of ions in a crystal lattice depends on the relative sizes of the ions

GIANT IONIC CRYSTAL LATTICE Each Na + is surrounded by 6 Cl¯ (co-ordination number = 6) and each Cl¯ is surrounded by 6 Na + (co-ordination number = 6). Oppositely charged ions held in a regular 3-dimensional lattice by electrostatic attraction The arrangement of ions in a crystal lattice depends on the relative sizes of the ions

Dot-and-cross diagrams of CaO

Dot-and-cross diagrams of AIF 3

Draw dot-and-cross diagrams to show the ionic bonding in: a) potassium chloride, KCl b) magnesium chloride, MgCl2 c) lithium sulphide, Li 2 S d) sodium sulphide, Na 2 S

Predicting ionic charges 1.Groups 1 to 3 usually form 1+ to 3+ ions 2.Groups 5 to 7 usually form 3- to 1- ions 3.Transition metals are DIFFERENT. They can often form many different ions, though often they are 2+ or 3+ 4.BUT Carbon, silicon and beryllium usually don’t form ions

Molecular ions Molecules as well as atoms can form ions Important examples include: Ammonium ion (NH 4 + ) Hydroxide (OH - ) Hydrogencarbonate (HCO 3 - ) Phosphate (PO 4 3- ) Think of 3 or more molecules that are charged.