Li, Na, K, Rb, Cs, Fr
The alkali metals are the elements that form group I of the periodic
table. The alkali metals react violently with water to form strong bases,
called alkalies. The alkali metals are monovalent, the outer electron shell
consisting of a single electron. This electron is easily shed to form a
stable cation that has the electron configuration of an inert gas. The
alkali metals readily donate electrons to Halogen atoms to form stable
salts. The reactivity of the alkali metals increases with atomic weight,
or increasing atom radius, because the outer electron is held less strongly.
Recent research has shown that atoms of alkali metals can also gain an
electron to form highly reactive anions.
Because
of their high reactivity, alkali metals are never found in nature as free
elements; instead they occur in compounds such as silicates or chlorides.
The alkali metals have low density, low melting point, and high ductility.
Name: Lithium
Symbol: Li
Atomic Number: 3
Atomic Weight: 6,941 g/mol
Oxidation States: 1
Boiling Point: 1615 K
Melting Point: 453,7 K
Density: 0,53 g/cm3
Electron Configuration: 1s2,2s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,98
Heat of Vaporization: 147,1 kJ/mol
Heat of Fusion: 3,0 kJ/mol
Electrical Conductivity: 11,7 106 (Om cm)-1
Thermal Conductivity: 84,7 W/(m K) (at 300
K)
Specific Heat Capacity: 3,582 J/(g K) (at
300 K)
First Ionization Potential: 5,392
Atomic Volume: 13,10 cm3/mol
Atomic Radius: 1,55 A
Covalent Radius: 1,23 A
Synthetic: No
Discovery: 1817; Arfvedson; Stockholm, Sweden
Note: soft metal, reacts slowly with oxygen
and water; used in medicine, batteries, and grease products
Name: Sodium
Symbol: Na
Atomic Number: 11
Atomic Weight: 22,98977 g/mol
Oxidation States: 1
Boiling Point: 1156 K
Melting Point: 371,0 K
Density: 0,97 g/cm3
Electron Configuration: [Ne]3s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,93
Heat of Vaporization: 98,01 kJ/mol
Heat of Fusion: 2,601 kJ/mol
Electrical Conductivity: 20,1 106 (Om cm)-1
Thermal Conductivity: 141 W/(m K) (at 300
K)
Specific Heat Capacity: 1,23 J/(g K) (at 300
K)
First Ionization Potential: 5,139
Atomic Volume: 23,70 cm3/mol
Atomic Radius: 1,90 A
Covalent Radius: 1,23 A
Synthetic: No
Discovery: 1897; by Davy in London, England
Note: soft, very reactive metal; reacts rapidly
with water; found in many salts; used by chemists to manufacture many chemicals
Name: Potassium
Symbol: K
Atomic Number: 19
Atomic Weight: 39,0983 g/mol
Oxidation States: 1
Boiling Point: 1033 K
Melting Point: 336,8 K
Density: 0,86 g/cm3
Electron Configuration: [Ar]4s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,82
Heat of Vaporization: 76,9 kJ/mol
Heat of Fusion: 2,33 kJ/mol
Electrical Conductivity: 16,4 106 (Om cm)-1
Thermal Conductivity: 102,5 W/(m K) (at 300
K)
Specific Heat Capacity: 0,757 J/(g K) (at
300 K)
First Ionization Potential: 4,341
Atomic Volume: 45,30 cm3/mol
Atomic Radius: 2,35 A
Covalent Radius: 2,03 A
Synthetic: No
Discovery: 1807; by Davy in London, England
Note: very soft metal; reacts rapidly with
water; used in fertilizers and glass
Name: Rubidium
Symbol: Rb
Atomic Number: 37
Atomic Weight: 85,4678 g/mol
Oxidation States: 1
Boiling Point: 961 K
Melting Point: 312,63 K
Density: 1,532 g/cm3
Electron Configuration: [Kr]5s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,82
Heat of Vaporization: 69,2 kJ/mol
Heat of Fusion: 2,34 kJ/mol
Electrical Conductivity: 47,8 106 (Om cm)-1
Thermal Conductivity: 58,2 W/(m K) (at 300
K)
Specific Heat Capacity: 0,363 J/(g K) (at
300 K)
First Ionization Potential: 4,177
Atomic Volume: 55,9 cm3/mol
Atomic Radius: 2,48 A
Covalent Radius: 2,16 A
Synthetic: No
Discovery: 1861; Bunsen & Kirchoff; Germany
Note: very soft, shiny metal; ignites in air
and explodes in water; Rubidium is rarely used
Name: Cesium
Symbol: Cs
Atomic Number: 55
Atomic Weight: 132,9054 g/mol
Oxidation States: 1
Boiling Point: 944 K
Melting Point: 301,54 K
Density: 1,87 g/cm3
Electron Configuration: [Xe]6s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,79
Heat of Vaporization: 67,740 kJ/mol
Heat of Fusion: 2,092 kJ/mol
Electrical Conductivity: 5,3 106 (Om cm)-1
Thermal Conductivity: 35,9 W/(m K) (at 300
K)
Specific Heat Capacity: 0,24 J/(g K) (at 300
K)
First Ionization Potential: 3,894
Atomic Volume: 70 cm3/mol
Atomic Radius: 2,67 A
Covalent Radius: 2,35 A
Synthetic: No
Discovery: 1860; Bunsen & Kirchoff; Germany
Note: soft, gold colored metal; explodes in
water; used in special glass and to monitor radioactive materials
Name: Francium
Symbol: Fr
Atomic Number: 87
Atomic Weight: 223 (most stable) g/mol
Oxidation States: 1
Boiling Point: 950 K
Melting Point: 300 K
Electron Configuration: [Rn]7s1
Acid/Base Properties: Basic
Crystal Structure: Cubic, body centered
Electronegativity: 0,7
Heat of Vaporization: 64 kJ/mol
Heat of Fusion: 2,1 kJ/mol
Thermal Conductivity: 15 W/(m K) (at 300 K)
Atomic Radius: 2,7 A
Synthetic: No
Discovery: 1939; by Perey in Paris, France
Note: metal; very radioactive; extremely rare;
traces can be found in uranium ore
