Chemical & Physical Properties
Atomic Number: 30
Atomic Weight: 65.39
Discovery: known since prehistoric time
Electron Configuration: [Ar] 4s2 3d10
Word Origin: German zinke: of obscure origin, probably German for tine. Zinc metal crystals are sharp and pointed. It could also be attributed to the German word 'zin' meaning tin.
Isotopes: There are 30 known isotopes of zinc ranging from Zn-54 to Zn-83 . Zinc has five stable isotopes: Zn-64 (48.63%), Zn-66 (27.90%), Zn-67 (4.10%), Zn-68 (18.75%) and Zn-70 (0.6%).
Properties: Zinc has a melting point of 419.58°C, boiling point of 907°C, specific gravity of 7.133 (25°C), with a valence of 2. Zinc is a lustous blue-white metal. It is brittle at low temperatures, but becomes malleable at 100-150°C. It is a fair electrical conductor. Zinc burns in air at high red heat, evolving white clouds of zinc oxide.
Sources: The primary ores of zinc are sphalerite or blende (zinc sulfide), smithsonite (zinc carbonate), calamine (zinc silicate), and franklinite (zinc, iron, and manganese oxides). An old method of producing zinc was by reducing calamine with charcoal. More recently, it has been obtained by roasting the ores to form zinc oxide and then reducing the oxide with carbon or coal, followed by distillation of the metal.
Density (g/cc): 7.133
Melting Point (K): 692.73
Boiling Point (K): 1180
Appearance: Bluish-silver, ductile metal
Atomic Radius (pm): 138
Atomic Volume (cc/mol): 9.2
Covalent Radius (pm): 125
Ionic Radius: 74 (+2e)
Specific Heat (@20°C J/g mol): 0.388
Fusion Heat (kJ/mol): 7.28
Evaporation Heat (kJ/mol): 114.8
Debye Temperature (K): 234.00
Pauling Negativity Number: 1.65
First Ionizing Energy (kJ/mol): 905.8
Oxidation States: +1 and +2. +2 is the most common.
Lattice Structure: Hexagonal
Lattice Constant (Å): 2.660
CAS Registry Number:7440-66-6
- Zinc is the 24th most abundant element in the Earth's crust.
- Zinc is the fourth most common metal used today (after iron, aluminum and copper).
- Zinc exposed to air will form a layer of zinc carbonate by reacting with carbon dioxide. This layer protects the metal from further reactions with air or water.
- Zinc burns white-green in a flame test.
- Zinc is the last period four transition metal.
- Zinc oxide (ZnO) was once called "philosopher's wool" by alchemists because it looked like wool when collected on a condenser after burning zinc metal.
- Half of the zinc produced today is used to galvanize steel to prevent corrosion.
- The U.S. penny is 97.6% zinc. The other 2.4% is copper.