Overview
This lecture introduces the chemical characteristics, oxidation states, colors, and uses of the Period 4 transition metals, highlighting their roles in industry and daily life.
Scandium (Sc)
- Scandium is a rare, soft silvery metal, primarily found in the +3 oxidation state.
- Its compounds are usually white due to filled d orbitals.
Titanium (Ti)
- Titanium is a strong, low-density, silvery metal used in jet engines and cosmetics.
- Different oxidation states cause different compound colors, e.g., Ti^4+ is colorless, Ti^3+ compounds can be purple.
Vanadium (V)
- Vanadium is a soft, ductile, silvery-white metal, most stable at the +5 oxidation state.
- Forms colorful salts; different oxidation states yield varied colors (e.g., V^2+ is violet).
- Used in steel alloys for jet engine parts and ceramics.
Chromium (Cr)
- Chromium is a rare, hard, brittle metal named for its colorful compounds.
- Common oxidation states: +2, +3 (green in solution), +6.
- Used in industrial materials for corrosion resistance.
Manganese (Mn)
- Manganese is a hard, brittle, gray-white metal reactive in oxidation states +2 to +7.
- Produces different colored compounds (e.g., Mn^7+ is purple).
- Used in steel production, magnets, paints, and as a dietary supplement.
Iron (Fe)
- Iron is the most abundant heavy metal, highly reactive and forms oxides.
- Exists mainly in +2 and +3 oxidation states; compounds have various colors.
- Essential for structural steel, automotive parts, and oxygen transport in blood.
Cobalt (Co)
- Cobalt is a rare, bluish-white metal used in alloys and as a chemical catalyst.
- Common oxidation states: +2, +3; important in vitamin B12.
- Named after the German word for goblin due to toxic mining fumes.
Nickel (Ni)
- Nickel is a silvery white metal with high conductivity and corrosion resistance.
- Typically forms +2 oxidation state compounds (green, yellow, blue colors).
- Used in coins, batteries, instruments, and surface coatings.
Copper (Cu)
- Copper is abundant, reddish-brown, highly conductive, and corrosion-resistant.
- Most stable as +2 oxidation state; forms blue, black, or green compounds.
- Used for wiring, coins, sculptures, and is often alloyed (brass, bronze).
Zinc (Zn)
- Zinc is a white, lustrous, highly active metal used for galvanizing steel.
- Exists in the +2 oxidation state, forming colorless salts.
- Essential for enzymes and immune support; found in batteries and sunscreens.
Key Terms & Definitions
- Transition Metal — an element with partially filled d orbitals, typically found in the center of the periodic table.
- Oxidation State — the charge an atom would have if all bonds were ionic.
- Alloy — a mixture of two or more metals.
- Galvanizing — coating a metal (usually steel) with zinc for protection from corrosion.
Action Items / Next Steps
- Review the oxidation states and uses for each Period 4 transition metal.
- Prepare for lab identification of transition metals by their compound colors.
- Read Chapter 19 for additional details on transition metals.