Periodic Table

• Who was the first to create a table of elements and how many elements did it list?

  Lavoisier created a table of elements listing 33 elements.
• What concept did Dobereiner introduce?

  Dobereiner introduced the concept of Triads.
• What is an example of a triad according to Dobereiner?

  An example of a triad is the "Iron Triad," which includes iron (Fe), cobalt (Co), and nickel (Ni).
• What did Newlands develop regarding the arrangement of elements?

  Newlands developed the Law of Octaves.
• What does the Law of Octaves suggest about elements?

  The Law of Octaves suggests that elements repeat their properties every eighth element when arranged by atomic weight.
• Who formulated the First Periodic Law and what does it state?

  Meyer & Mendeleev formulated the First Periodic Law, stating that the properties of elements are periodic functions of their atomic weights.
• Who created the first Modern Periodic Table?

  Moseley created the first Modern Periodic Table.
• How did Moseley group elements in the Modern Periodic Table?

  Moseley grouped elements so that every set of 8 elements was followed by another set of 8 elements.
• What are the periodic trends in atomic radius?

  • Defined as half the distance between the nuclei of two atoms.
  • Increases from right to left across a period.
  • Increases from top to bottom down a group.
• What is electronegativity and how does it vary in the periodic table?

  • Electronegativity is the ability of an atom to attract electrons.
  • Increases from left to right across a period.
  • Increases from bottom to top up a group.
• What is ionization energy and its trend in the periodic table?

  • Ionization energy is the energy required to remove an electron from a positively charged atom.
  • Increases from left to right across a period.
  • Increases from bottom to top up a group.
• What is electron affinity and how does it change in the periodic table?

  • Electron affinity is the tendency of an atom to accept an electron.
  • Increases from left to right across a period.
  • Increases from bottom to top up a group.
• What is the Periodic Table?

  • Arrangement of known elements based on atomic number
  • Organized by chemical and physical properties
  • Useful for predicting chemical behavior and trends
• How many elements are there in the Periodic Table?

  118 elements
• What are the three basic categories of elements in the Periodic Table?

  • Metals
  • Non-metals
  • Metalloids
• How is the Periodic Table organized?

  • Atomic Structure
  • Atomic Number
  • Chemical and Physical Properties
• What are elements defined as in chemistry?

  Atoms of only one type identified by atomic number
• Where are electrons arranged in an atom?

  • In a region around the nucleus called the electron cloud
• What happens to the energy of electrons as they are arranged further from the nucleus?

  Electrons in levels further away from the nucleus have more energy
• What are valence electrons?

  Electrons in the outermost energy level that determine the reactivity of an element
• What is the rule for filling energy levels in an atom?

  • Inner levels will fill first before outer levels
• How many electrons can each energy level hold?

  • 1st level: up to 2
  • 2nd level: up to 8
  • 3rd level: up to 8 (first 18 elements only)
• What are groups in the Periodic Table?

  • Vertical columns grouped by similar properties
  • Numbered from 1 to 18
  • Elements in the same group have the same number of valence electrons
• How many valence electrons does Group 1 have?

  1 valence electron
• How many valence electrons does Group 2 have?

  2 valence electrons
• What is the range of valence electrons for Groups 3-12?


  1 or 2 valence electrons
• How many valence electrons does Group 13 have?


  3 valence electrons
• How many valence electrons does Group 15 have?

  5 valence electrons
• How many valence electrons does Group 18 have?

  8 valence electrons
• What is reactivity in terms of elements?

  • A chemical property that determines how elements react with others to form compounds
• What factors make an element reactive?

  • Number of valence electrons
  • Stability when outer levels are full
  • Reactivity when outer levels are not full (gain, lose, or share electrons)
• What does GEROA stand for?

  • Gain Electron
  • Reduction
  • Oxidizing Agent
• What does VILEORA stand for?

  • Valence Increase
  • Lose Electrons
  • Oxidation
  • Reducing Agent
• Which groups contain the most reactive metals?

  • Group 1 (needs 7 more electrons)
  • Group 2 (needs 6 more electrons)
• Which groups contain the most reactive non-metals?

  • Group 6 (needs 2 more electrons)
  • Group 7 (needs 1 more electron)
• What are the properties of Group 1: Alkali Metals?

  • Contains: Metals
  • Valence Electron: 1
  • Reactivity: Very Reactive
  • Properties: Solids, soft, react violently with water, shiny, low density
• What are the properties of Group 2: Alkali Earth Metals?

  • Contains: Metals
  • Valence Electron: 2
  • Reactivity: Very reactive but less than Group 1
  • Properties: Solids, silver colored, denser than Group 1
• What are the properties of Groups 3-12: Transition Metals?

  • Contains: Metals
  • Valence Electron: 1 or 2
  • Reactivity: Less reactive than Groups 1 and 2
  • Properties: Higher density, good conductors of electricity and heat
• What are the Lanthanide and Actinide Series?

  • Lanthanides: #’s 58–71
  • Actinides: #’s 90–103
• Why are the Lanthanide and Actinide Series separated from the main table?

  • To keep the table from being too wide