Chapter 13.1 Flashcards
**First-Row D Block Elements **
What are the first 10 d block elements
The elements strating from Sc to Zn
**First-Row D Block Elements **
What is special about the first 10 d block elements?
Have similar chemical and physical properties
Transition Elements Have Characteristic Properties (Electron Config)
How is the similarity between the the first 10 d block elements shown?
Due to their relatively small atomic radii
Transition Elements Have Characteristic Properties (Electron Config)
What is the reason for the decrease of the atomic radii of the d block elements across a period?
Due to the slight increase in effective nuclear charge experienced by 4s electrons
Transition Elements Have Characteristic Properties (Electron Config)
Why are transition metals able to form alloys?
Due to their similarity atomic radii which will not cause disruption of the solid structure
Physical Properties
What are the physical properties of transition elements?
-High thermal and electrical conductivity
-High melting point
-Malleable
-High tensile strength
-Ductile
Physical Properties
What allows the transition metals to have these physical properties?
Due to strong metallic bonding found in elements, which involves the 3d and 4s electrons being close in energy and form part of the delocalized sea of electrons which hold lattice together
Physical Properties
What gives transition metals their strong metallic bonding and electrical conductivity?
Large number of delocalized electrons
Chemical Properties
What are the chemical properties of transition metals?
-Form more than one oxidation number
-Form a variety of complex ions
-Form colored compounds
-Act as catalysts
Zinc is not a Transition Metal
Why is zinc not a transition metal?
It does not displlay any of the chemical properties of a transition metal and only has one oxidation number of +2
Zinc is not a Transition Metal
What evidence shows that Zinc is nota transition metal?
The fact that Zn’s atom and ion both complete the d sublevel
Zinc is not a Transition Metal
What can the definition of a transition metal then be defined as?
Elements whose atoms have an incomplete d-sublevel, or give rise to cations with incomplete d-sublevel
Explanation of Variable Oxidation Number of Transition Elements
What is the oxidation number of an element related to?
The successive ionization energies
Explanation of Variable Oxidation Number of Transition Elements
What oxidation numbers do all transition metals show?
+2 and +3, where the M3+ is the most stable state of elements from scandium to chromium
Explanation of Variable Oxidation Number of Transition Elements
How do the oxidation states increase and where do they reach a maximum?
They increase by a factor of +1 until magnesium, where the increasing oxidation states correspond to the use of 4s and 3d electrons in bonding
Explanation of Variable Oxidation Number of Transition Elements
What is special about ions that have an oxidation number of +3 or higher?
They show covalent character as they are able to polarize negative ions and increase covalent character of compound
Explanation of Variable Oxidation Number of Transition Elements
What are compounds with higher oxidation states used as?
Oxidizing agents
Complex Ions
What is a complex ion?
It is when transition metal ions have a high charge density and are able to attract water molecules which form coordinate bond with positive ion
Complex Ions
What is the more general definition of a complex ion?
When a central ion is surrounded by molecules or ions which possess a lone pair of electrons
Complex Ions
What are the species surrounding the central ion?
Ligands which attach by coordinate covalent bonding
Complex Ions
What is the coordination number?
The number of coordinate bonds from ligand to central ion
Polydentate Ligands Act as Chelating Agents
What is a polydentate?
Species that have more than one lone pair available to form more than one coordinate bond with central ion
Polydentate Ligands Act as Chelating Agents
What is a chelate?
A complex containing at least one polydentate ligang
Transition Metals and their Ions as Heterogeneous Catalysts
What is a heterogeneous catalyst?
The catalyst is a different state from the reactants
Transition Metals and their Ions as Heterogeneous Catalysts
What makes transition elements good heterogeneous catalysts?
They have the ability to use 4d and 3s electrons to form weak bonds with reactant, providing a surface for the reactant molecules to come together with correct orientation
Transition Metals and their Ions as Heterogeneous Catalysts
What are examples of heterogenous catalysts?
-Iron in Haber process
-Nickel in the conversion of alkenes to alkanes
-Palladium in catalytic converters
-Magnesium oxide in the decomposition hydrogen peroxide
-V2O5 in Contact process
Ions of Transition Metals as Homogeneous Catalysts
What are homogenous catalysts?
They are in the smae state of matter as the reactants
Ions of Transition Metals as Homogeneous Catalysts
What makes tranistion metals good homogenous catalysts
The fact that they are able to display many oxiadation states
The Magnetic Properties of the Transition Metals and their Compounds
What is special about the electrons in the atoms of transition elements
Some are unpaired, leading to magnetic properties when faced by external magnetic force
The Magnetic Properties of the Transition Metals and their Compounds
What are the different behaviors to an external magnetic field
-Diamegnetism
-Paramagnetism
-Ferromagnetism
The Magnetic Properties of the Transition Metals and their Compounds
What is diamegnetism?
It is a property of all materials and produces a very weak opposition to an applied magnetic field. They oppose external magnetic field
The Magnetic Properties of the Transition Metals and their Compounds
What is paramagnetism?
Only occurs with materials that have unpaired electrons. It produces magnetization proportional to that of external force and in the same drection
The Magnetic Properties of the Transition Metals and their Compounds
What is ferromagntism?
Produces magnetiations often greater than the applied field. happnes when there is a long range ordering of unpaired electrons
The Magnetic Properties of the Transition Metals and their Compounds
How are iron, cobalt and nickel ferromagnetic
The upaired d electrons in large numbers line up with parallel spins in regions known as domains, which become more ordered if exposed to external magnetic field. After the external magnetic field is removed, the magnetism remains due to long range interactions between upaired electrons and in different atoms
