periodic table

• How many naturally occurring elements are there?

  92
• Why are elements arranged in the periodic table?

  By atomic mass, from lightest to heaviest
• What fraction of the elements are metals?

  About three quarters
• Why are elements grouped in the periodic table?

  They have similar properties
• What does the big number next to each element represent?

  Relative atomic mass
• What does the small number next to each element represent?

  Atomic number
• What is the atomic number of hydrogen?

  1
• What are the groups in the periodic table?

  Vertical columns with similar properties
• What are the names of the blocks in the periodic table?

  S block, P block, D block, F block
• What is ionization energy?

  Energy needed to remove an electron
• What is the first ionization energy?

  Energy to remove one electron from an atom
• Which atoms have small ionization energy?

  Atoms with one or two outer electrons
• Which atoms have large ionization energy?

  Atoms with nearly full outer shells
• How does ionization energy change across a period?

  It increases from left to right
• How does ionization energy change down a group?

  It decreases as you go down
• What is electron affinity?

  Energy released when an atom gains an electron
• Which type of atoms typically have high electron affinity?

  Non-metals
• Which group has the highest electron affinity?

  Group seven (halogens)
• How does electron affinity relate to ionization energy?

  It's almost the opposite of ionization energy
• What happens when a neutral atom gains an electron?

  Energy is released
• What should you focus on regarding electron affinity?

  Non-metals, not metals
• What are the trends in ionization energy across periods and down groups?

  • Across a period: Ionization energy increases
  • Down a group: Ionization energy decreases
• What are the key properties of the periodic table?

  • Arranged by atomic mass
  • Groups have similar properties
  • Metals make up about three quarters
  • Contains blocks: S, P, D, F
• What is the relationship between atomic structure and ionization energy?

  • More protons = higher ionization energy
  • Electrons further from nucleus = lower ionization energy
• What is the relationship between electron affinity and non-metals?

  • Non-metals have high electron affinity
  • They release energy when gaining electrons