C3 bonding

Cards (71)

  • ionic bonding occurs between metals and non-metals
  • in ionic bonding, electrons are transferred from metal atoms to non-metal atoms to achieve full outer shells, forming positive and negative ions
  • in ionic compounds, oppositely charged ions are attracted to each other by electrostatic forces, forming a giant ionic lattice, this is a 3D structure
  • the formula of a sulfate ion is SO4(2-)
    the formula of a hydroxide ion is OH(-)
    the formula of a nitrate ion is NO3(-)
    the formula of a carbonate ion is CO3(2-)
    the formula of an ammonium ion is NH4(+)
  • covalent bonding occurs between non-metals and other non-metals
  • in covalent bonding, electrons are shared between the two outer shells to achieve full outer shells
  • multiple electron pairs can be shared to produce multiple covalent bonds
  • coordinate bonding is a form of covalent bonding where both electrons in the shared pair are supplied from a single atom
  • coordinate bonds react in the exact same way as covalent bonds
  • in a diagram, covalent bonds are shown with a line, coordinate bonds are shown with an arrow
  • metallic bonding occurs between metals and other metals
  • in metallic bonding, the greater the charge of the positive ion, the stronger the electrostatic forces as more electrons are released into the sea
  • in metallic bonding, a sea of delocalised electrons surrounds a lattice of positive ions, held together by strong electrostatic forces of attraction between negative electrons and positive ions
  • the larger the positive ion, the weaker the electrostatic forces as the nucleus is further from the delocalised electrons
  • electronegativity is the ability of an atom to attract the electron density in a bond, the bonding pair of electrons, towards itself
  • electronegativity increases going up a group because atoms get smaller, and there is less shielding
  • electronegativity increases going across a period because nuclear charge increases, atoms gets smaller, but number of energy levels is constant
  • the most electronegative atom is F, then O, N, Cl
  • the negative charge in a covalent bond is not distributed evenly, unless both atoms are of the same element, as different atoms have different electronegativities
  • covalent bonds are polar, and increase in polarity as the difference in electrnoegativity of the atoms increases
  • there are 3 types of intermolecular forces:
    • van der Waals
    • dipole-dipole
    • hydrogen bonding
  • van der Waals forces act between all atoms and molecules
  • van der Waals forces are the weakest type of intermolecular force
  • as Mr increases, strength of van der Waals forces increases, as there are more electrons
  • compounds with unbranched molecules have stronger van der Waals than compounds with branched molecules because the straight molecules can pack closer together
  • dipole-dipole forces act between molecules with a polar bond
  • in a polar bond, the delta-positive and delta-negative regions attract each other, holding the molecules together
  • hydrogen bonds form between hydrogen atoms and either fluorine, oxygen, or nitrogen atoms
  • hydrogen bonds are the strongest type of intermolecular force
  • to form a hydrogen bond, the lone pair on the fluorine/oxygen/nitrogen of one molecule is attracted to the hydrogen of another molecule
  • to draw hydrogen bonds:
    • show the bond as a dotted line
    • it must be 180 degrees
    • label the delta-positive and delta-negative regions
  • molecules form different shapes depending on the number of bonding pairs and lone pairs they have, and the shapes have specific angles
  • 2BP and 0LP:
    name = linear
    angle = 180
  • 3BP and 0LP:
    • name = trigonal planar
    • angle = 120
  • 4BP and 0LP:
    name = tetrahedral
    angle = 109
  • 5BP and 0LP:
    • name = trigonal bipyramidal
    • angles = 120 and 90
  • 6BP and 0LP:
    • name = octahedral
    • angle = 90
  • 2BP and 1LP:
    • name = bent
    • angle = <120
  • 3BP and 1LP:
    • name = trigonal pyramidal
    • angle = 107
  • 4BP and 1LP:
    • name = seesaw
    • angles = <120 and <90