Periodic Table

• Periodic table


  A tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson
• The atomic number of an element, representing the number of protons in the nucleus of an atom of that element, ranges from 1 for hydrogen to 118 for oganesson
• Periodic table


  • Allows for systematic classification and arrangement of elements based on their atomic properties, facilitating predictions of their chemical behavior and properties
• Development of the periodic table

  1. Contributions of multiple scientists over several centuries

  2. Concept of organizing chemical elements into a table based on their properties dates back to the late 18th century
• Scientists who contributed to the development of the periodic table

  • Antoine Lavoisier
  • John Dalton
  • Johann Wolfgang Döbereiner
  • Alexandre-Émile Béguyer de Chancourtois
  • John Newlands
  • Dmitri Mendeleev
  • Henry Moseley
• Periodic table groups


  Also known as columns or families, share similar chemical properties because they have the same number of valence electrons
• Valence electrons


  The electrons in the outermost shell of an atom, determining an element's reactivity and chemical behaviour
• The periodic table splits to accommodate the transition metals, which have unique properties distinct from those of the main group elements
• Periods


  Horizontal rows in the periodic table, corresponding to the filling of a principal energy level with electrons
• Groups


  Vertical columns in the periodic table, having similar chemical properties due to similar electron configurations
• Periodic trends


  • Atomic number
  • Atomic radius
  • Atomic mass
  • Ionization energy
  • Electronegativity
• Types of elements


  • Metals
  • Non-metals
  • Metalloids
• Main groups of the periodic table

  • Alkali metals (Group 1)
  • Alkaline earth metals (Group 2)
  • Transition metals (Groups 3-12)
  • Halogens (Group 17)
  • Noble gases (Group 18)
• Main groups


  • Reactivity: Alkali metals are highly reactive, while noble gases are inert (stable)
  • Chemical behavior: Alkali metals readily form ions with a +1 charge, while halogens tend to form ions with a -1 charge
  • Common oxidation states: Transition metals often exhibit multiple oxidation states, while noble gases have no common oxidation states
• The first 20 elements

  • Hydrogen
  • Helium
  • Lithium
  • Beryllium
  • Boron
  • Carbon
  • Nitrogen
  • Oxygen
  • Fluorine
  • Neon
  • Sodium
  • Magnesium
  • Aluminum
  • Silicon
  • Phosphorus
  • Sulfur
  • Chlorine
  • Argon
  • Potassium
  • Calcium
• Properties and uses of the first 20 elements

  • Hydrogen: Used in petroleum refining, ammonia production
  • Helium: Used in cryogenics, helium-neon lasers
  • Lithium: Used in rechargeable lithium-ion batteries, psychiatric medications, and lithium grease production
  • Beryllium: Utilized in aerospace components, nuclear reactors, and X-ray windows
  • Boron: Employed in borosilicate glass, boron fibers for aerospace, and neutron shielding
  • Carbon: Used in steel production, carbon fiber manufacturing
  • Nitrogen: Used in fertilizer production, food packaging
  • Oxygen: Used in steelmaking, medical oxygen
  • Fluorine: Used in toothpaste, fluoridation of water
  • Neon: Used in neon signs, lighting
  • Sodium: Used in food processing, chemical manufacturing
  • Magnesium: Used in alloy production, fireworks
  • Aluminum: Used in aerospace industry, beverage cans
  • Silicon: Used in semiconductor manufacturing, glass production
  • Phosphorus: Used in fertilizer production, flame retardants
  • Sulfur: Used in sulfuric acid production, vulcanization of rubber
  • Chlorine: Used in water treatment, disinfectants
  • Argon: Used in welding, lighting
  • Potassium: Used in fertilizer production, soap manufacturing
  • Calcium: Used in construction materials, bone health supplements