Bonding

• What type of bonding occurs between metals and non-metals?

  Ionic bonding
• What happens to electrons in ionic bonding?

  Electrons are transferred from metal to non-metal
• What charge does a metal ion form in ionic bonding?

  Positive ion
• What charge does a non-metal ion form in ionic bonding?

  Negative ion
• What structure do ionic compounds form?

  Giant ionic lattice
• Why is the ionic lattice described as 'giant'?

  Same basic structure is repeated many times
• Why do ionic compounds dissolve in water?

  Water's polarity attracts positive and negative ions
• Why can ionic compounds conduct electricity when molten or dissolved?


  Because ions are free to move around
• What is the melting point characteristic of ionic compounds?

  Very high melting points
• How does atomic radius affect ionic bonding strength?

  Smaller ions mean stronger ionic bonding
• What is a coordinate bond?

  When the shared pair of electrons in the covalent bond is supplied by one atom
• Why do smaller ions lead to stronger ionic bonding?

  They are packed closely in a lattice
• How is ammonia formed in terms of coordinate bonding?

  Lone pair of nitrogen is shared with the hydrogen
• What happens to ionic bonding strength down a group?

  It becomes weaker due to increased shielding
• What happens to ionic bonding strength across a period?

  It becomes stronger due to higher nuclear charge
• What are simple molecules?

  Molecules with two or more atoms bonded together
• What type of bonds hold simple molecules together?

  Covalent bonds between atoms
• What forces need to be broken to melt or boil simple molecules?

  Intermolecular forces between molecules
• What are giant covalent structures?

  • Huge network of covalently bonded atoms
  • Carbon can form 4 strong covalent bonds
• What is the structure of diamond?

  Tetrahedral shape as each carbon is covalently bonded to 4 other carbons
• Why do giant covalent structures have very high melting and boiling points?

  Due to strong covalent bonds between atoms
• Why can't diamond conduct electricity?

  There are no delocalised electrons
• Why can graphite conduct electricity?

  It has delocalised electrons that move and carry charge
• What does metallic bonding consist of?

  Electrostatic forces of attraction between positive metal ions and delocalised electrons in a lattice
• What structure do metals exist as?

  Giant lattice structures
• What happens to the outermost electron in a metal atom?

  It becomes delocalised and free to move
• How do lone pairs affect molecular shape?

  Lone pairs repel more than bonding pairs, reducing bond angles by 2.5 for each lone pair
• What is electronegativity?

  Power of the atom to attract the pair of electrons in a covalent bond towards itself
• Which element is the most electronegative?

  Fluorine
• How does electronegativity change in the periodic table?

  Increases up and to the right
• What happens to bond polarity with increasing electronegativity difference?

  Bond becomes more polar
• What are Van der Waals forces?

  Weak forces between atoms and molecules
• How do Van der Waals forces arise?

  From temporary dipoles in molecules due to uneven distribution of electrons
• What happens to Van der Waals forces when molecules are larger?

  They increase due to more electrons
• What defines dipole-dipole interactions?

  Polar molecules with permanent dipoles
• What is hydrogen bonding?

  A strong type of dipole-dipole force
• Which elements are involved in hydrogen bonding?

  Nitrogen, oxygen, and fluorine
• How does atomic radius affect electronegativity?

  Smaller atomic radius increases electronegativity
• How does nuclear charge affect electronegativity?

  Higher nuclear charge increases electronegativity
• How does shielding affect electronegativity?

  More shielding decreases electronegativity