Periodic table trends Answers

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Periodic table trends Answers
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Ionization energy vs. atomic number
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Trends in Ionization Energy

• Noble gases exhibit the highest ionization energy
• Alkali metals exhibit the lowest ionization energy

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Atomic radius vs. atomic number
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Trends in Atomic Radius

• Alkali metals have the largest atomic radii
• Noble gases have the smallest atomic radius
• Atomic radius is inversely related to ionization
  energy.
• As atomic radius increases, ionization energy
  decreases.

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Atomic Radius

• One half the distance between nuclei of identical
  atoms that are bonded together (the radius of an
  atom)
• Decreases across a period
• increasing positive nuclear charge
• more protons but same number of electron shells
• Increase down a group
• increasing number of electron shells
• outer electrons are farther from the nucleus

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Ionization Energy

• The energy required to remove an electron from a
  neutral atom
• IE increases across a period
• Atoms are getting smaller, electrons are closer
  to the nucleus, stronger attractive force
• IE decreases down a group
• Atoms are getting larger, electrons are farther
  from the nucleus
• Outer electrons becomes increasingly more
  shielded from the nucleus by inner electrons
• Metals have characteristically low IE
• Nonmentals have high IE
• Noble gases have a very high IE
• Stable octet, full valence shell

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Ionic Radius

• Radius of an ion (an atom that has gained or lost
  electrons)
• Cations have a smaller ionic radius than
  corresponding atom
• Protons outnumber electrons
• Less shielding of electrons
• Therefore, stronger attractive forces
• Anions have a larger ionic radius than
  corresponding atom
• Electrons outnumber protons
• Greater electron-electron repulsion
• Therefore, weaker attractive forces

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Electron Affinity

• An atoms ability to attract an electron
• Increases across a period
• Atomic radius decreases, stronger attractive
  forces
• Decreases down a group
• Atomic radius and shielding by inner electrons
  increases, weaker attractive force

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Electronegativity

• An atoms ability to attract electrons when
  bonded
• We will explore this more later

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Electronegativity
Electronegativity