Transition metals are metallic elements in groups IB – VIIIB characterised by metallic bonding, coloured compounds, varying oxidation states and catalytic ability.
Transition metals have high electric conductivity due to the free flowing outer d-orbital electrons. They have low electron affinity, low ionization energy, and low electronegativity. They have high melting and boiling points. Transition metals have different possible oxidation states because they are capable of losing different numbers of electrons from the s- and d-orbitals in their valence shells. One example is the element copper (Cu). It can exist in either the +1 or +2 oxidation state. Manganese (Mn) can exist in the +2, +3, +4, +6, or +7 oxidation state. These different oxidation states often allow these elements to have vibrant colors when forming compounds. Transition metals and their complexes are also commonly used as catalysts.
Practice Questions
Khan Academy
MCAT Official Prep (AAMC)
Chemistry Question Pack Passage 3 Question 14
Key Points
• Transition metals have high electric conductivity; but they have low electron affinity, low electronegativity, and low ionization energy
• They have high melting and boiling points
• Transition metals have different possible oxidation states because of the different number of valence electrons in the s- and d- orbitals
Key Terms
valence electron: an outer shell electron that can participate in chemical bonds
ionization energy: the energy required to remove an electron from the valence shell of a gaseous atom
electron affinity: the energy change that occurs when an atom gains an electron
electronegativity: a measure of the ability of an atom to attract the electrons in a bond
oxidation state: a number assigned to an element in chemical combination which represents the number of electrons lost
d-orbital electrons: electrons contained in the d orbital
melting point: the temperature at which an element will melt
boiling point: the temperature at which an element will boil
catalyst: a substance that can be added to a reaction to increase the reaction rate
