Alkali Metals: Properties and Reactivity

Alkali Metals or Soluble Groups "ACTIVE ELEMENTS"

• Valence electron: 1
• Hydroxides and Oxides are STRONGLY BASIC
• SOFTER than most other metals
• Activity and Alkalinity increase with atomic number (↓A# = ↑Activity and Alkalinity)
• MOST REACTIVE metals, that DO NOT OCCUR FREELY in nature
• Degree of solvation (attract water) decrease with atomic number (↑A# = ↓Affinity/DS)
• React with HALOGEN to form SALTS
• React with OXYGEN and AIR forming BASIC OXIDES
• Hydrogen shares the same properties with alkali metal

Hydrogen

• Lightest Element
• HELIUM - 2nd Lightest Element
• Universe Most Abundant Element
• Density: 1 g/mL
• Method of preparation: LANE PROCESS and MESSERSCHMIDT PROCESS
• ISOTOPES of Hydrogen: PROTIUM (H2O), DEUTERIUM (D2O), and TRITIUM
• Named by: Antoine Laurent Lavoisier
• Discovered by: Henry Cavendish

Lithium

• 3rd Lightest Element
• Lightest Metal
• Density: 0.534 g/mL - float in water
• Derived: “lithos” - Stones
• Discovered by: J.A Arfwedson
• Atomic Number: 3
• Melting Point: 186°C
• Mass Number: 7
• Compounds: Lithium Bromide (LiBr), Lithium Carbonate (Li2CO3)
• Use: Heat exchanger in aircon, CNS Depressant, Diuretic

Sodium or Natrium

• The cation of choice to optimize the pharmaceutical utility of organic medicaments
• Modification: CESIUM color: BLUE, RUBIDIUM color: RED, FRANCIUM
• Discovered by Robert Bunsen and Gustav Kirchhoff

Silicon

• Glass: Na2(CO3) + Pure Silica
• Silica Gel Fume- Condensation of silica vapor
• Allotropic form: Silica gel - prepared by hydrolysis of inorganic or organic orthosilicates
• Amorphous silicon - Dark brown
• Crystalline or Semi-metallic silicon - Silvery octahedral crystals
• Toxicity: Silicosis - resembling TB symptoms that develops after long exposure
• Antidote: Alumina
• Compounds: Silicon Dioxide SiO2, Aluminum Silicates, Attapulgite ‘NHMAS’

Tin or Stannum

• Pharmacologic Action: Germicidal effect against Staphylococci
• Alloys of Tin: Babbitt, Gun Metal, Pewter Metal, Soldier, Plumber's Soldier, Rose Metal
• Compounds: Stannous Chloride (SnCl2), Stannous Fluoride (SnF2), Stannic Oxide (SnO2)

Lead or Plumbum

• Increase the Refractive Index of glass
• Source of poisoning: Lead Paints, Lead Batteries, Lead Pipes
• Toxicity: Plumbism
• Manifestation: Foot drop or Wrist drop, Burton line - blue line in gum with bluish-black edging to the teeth
• Antidote: EDTA and CaNa2 EDTA
• Compounds: Lead Acetate Pb(C2H3O2)2, Lead Subacetate Pb3(C4H10O8), Lead Monoxide (PbO)

Titanium or "Titans" Sons of the Earth

• Use: Powerful Reducing agent
• UV Radiation: UVA, UVB, UVC
• Compound: Titanium Dioxide (TiO2) Opacifying agent, Sunscreen