PERIODICITY and the PERIODIC TABLE

Periodicity Notes (HL) Complete the following notes by filling in the gaps, completing the equations as required and answering the questions. Refer to the textbook in completing this. Transition Elements (metals) – Period 4  List them – ______ In period 4, all the transition metals have _____ in the outer shell and progressively fill the _____ sub-shell as move from left to right. Write out the electronic configuration (in subshells) for Sc: ______Ti: ______V: ______Cr: ______Cu: ______Zn: ______ This means they have similar ______and ______properties.  Their Atomic radii is ______ Their First ionisation energy is ______

Characteristics of Transition Elements 1. variable ______states 2. form ______ions 3. form ______compounds 4. act as ______

two elements in Period 4 transition metals do not show these properties – ____ and ____, and so are not considered typical d-block or transitions elements. Why?? They are the first and last of the group therefore have an empty or full 3d sub-shell.

1. Oxidation states  All show an oxidation sate of ____ when they form the +2 ion, by losing the two _____ electrons e.g. Mn2=, Fe2+  Some are able to form other ions e.g. Cr3+, ______, ______These are the other oxidation states:

 Some may bond covalently up to 7 electrons (3d and 4s) enabling them to have oxidation states up to ______Must know the following: Cr (+3 and +6) Mn (+4 and +7) Fe (+3) Cu (+1) B/c both the 4s and UNPAIRED 3d electrons can be sued to form bonds

 Can you explain each of these oxidation states? e.g. Mn (+7) – Mn has . . . . 3d5 4s2 , all the 3d electrons are ______, therefore all 7 electrons can form covalent bonds so has an oxidation state of +7 Mn (+4) - Cr (+3) – 3d5 4s1 – ion where loses the one 4s electron and two 3d electrons as so close in energy Cr (+6) – can form ____ covalent bonds Fe (+3) - 3d6 4s2 , ion where two _____ electrons and one _____ electron are lost as energy levels close together Cu (+1) – 3d9 4s2 , an oddity as it is more stable to have ______, therefore loses the one 4s electron to form Cu+  Because of the variation in oxidation states, transition metals occur in many ______reactions

2. Formation of complex ions

 Dative or coordinate covalent bonding occurs when a species doesn’t have enough electrons to share to get a full outer shell so shares an unshared or lone pair of electrons from another molecule e.g. NH3

 A complex is formed when a d-block metal ion is surrounded by other molecules or ions, which form c______covalent bonds with the metal. The molecules or ions are called l______, and they all have a ______pair of electrons.

 The number of ligands surrounding the ion is usually 4 or 6. This is called the c______number. 3+ 3- 2- 2+ +  Examples: [Fe(H2O)6] , [Fe(CN)6] , [CuCl4] , [Cu(NH3)4] , [Ag(NH3)2]

 When the coordination is 6, the shape is o______. With 4, shape is usually t______or occasionally s______p______.

 When drawing complex molecules use dotted lines to show the dative bonding and make sure the lone pair of electrons point towards the metal ion. Draw diagrams of the five complex ions listed above. Name the ligand for each one. 3+ 2- [Fe(H2O)6] [CuCl4]

3- + [Fe(CN)6] [Ag(NH3)2]

2+ [Cu(NH3)4]

3. Form coloured compounds e.g. copper sulfate, nickel carbonate The d-block metal compounds absorb light because of electrons moving from one ___ orbital to another. Unlike in isolated atoms where all d orbitals have the same energy level, however when l______approach the metal atom or ion, they affect the energy levels of the different d orbitals, r______some slightly, l______some slightly. Therefore electrons may m_____ between them. Now if the frequency of this energy gap/jump is in the visible spectrum, the substance will be coloured. e.g. if the substance absorbs ______light, it will let red and blue light through thus appearing purple. Zn has no spaces in the 3d orbitals so electrons cannot ______therefore is not c______. 4. Catalysis Catalyst definition:

e.g. vanadium (V) oxide – V2O5 in the Contact process in the manufacture of sulfuric acid Equation: manganese (IV) oxide – MnO2 to decompose hydrogen peroxide Equation: Fe in the Haber process in the production of ammonia Equation: Ni in the conversion of alkenes to alkanes e.g. hydrogenation of oils in margarine Equation:

Transition metals and their compounds are important catalysts in industry and biological systems.

The catalytic activity of transition metals depends on their ability to exist in a number of o______states or in c______complexes. These form i______steps in which ______energy is required, so increases the rate.

Chlorides of the third period (Na  Ar)  Chlorides: giant ionic structures to molecular covalent

NaCl MgCl2 AlCl3 SiCl4 PCl3 SCl2 Cl2 Giant ionic I______Mainly M______l______c______lattice l______lattice  Those with a molecular structure have ______forces holding the molecules together, hence have a ______melting point.  Which of these chlorides could conduct electricity in the molten state? Explain.

 Phosphorus can form PCl5 as it has __ electrons in the outer shell. The bonds are formed due to one electron being promoted to the __ subshell then there are 5 single electrons, which can each form a c______bond (1 in 3s, 3 in 3p and 1 in 3d)  ______dissolves in water to give a neutral solution  ______produces a slightly acidic solution when dissolved in water  all other chlorides react with water to produce a______solutions due to the formation of h______acid and ______gas:

2AlCl3(s) + 3H2O(l ) ®

SiCl4(l ) + 4H2O(l ) ®

PCl3(l) + 3H2O(l ) ®  chlorine gas reacts slightly with water to forma an acidic solution

Cl2(aq ) + H2O(l ) «

Oxides of the third period  s block oxides react with water to form hydroxides hence called basic oxides:

Na2O + H2O  2NaOH

MgO + H2O   p block oxides: Al2O3 is a______

Al2O3(s) + HCl (aq) 

Al2O3(s) + 2KOH(aq) + 3 H2O  Silicon dioxide (______) is acidic:

SiO2(s) +

Phosphorus has 2 important oxides: phosphorus (III) oxide – P2O3 Phosphorus (V) oxide - P2O5

Both are a______– react with water to form p______acid (H3PO4)

Sulfur forms 2 oxides: sulfur dioxide – SO2 Sulfur trioxide – SO3 Both are acidic oxides - react with water to form sulfuric/sulfurous acid (imp. in acid rain)

SO2 + H2O 

SO3 + H2O 

______, dichlorine heptoxide is also an acidic oxide forming p______acid when it reacts with water

Cl2O7(l ) + H2O(l ) ®

 Describe the type of bonding that occurs in each of these oxides and explain how this determines the electrical conductivity of the oxide in the molten state?

 Which oxide would have the highest melting point? Explain. Which would have the lowest? Explain.