ionic and covalent bonding Flashcards
(17 cards)
what is a sigma bond
the head-on overlap of two orbital
what is a pi bond
the sideways overlap of two p orbitals
4 differences of ionic and covalent bonds
1 ionic: network of ions in the crystal
covalent: individual molecules
2 ionic: hard and brittle
coolant: soft
3 ionic: high melting point
covalent: low melting point
4 ionic: conducts electricity
covalent: does not conduct electricity
electronegativity
the relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond
ionic bonding
greater then 1.7
covalent bonding
less then or equal to 1.7
polar covalent
greater then 0.04 and less then 1.7
non-polar/ pure covalent
less then or equal to 0.04
a molecule such as BCl3 (no lone pairs) is what shape
trigonal planar
a molecule such as CH4 is what shape
tetrahedron
a molecule such as BeCl2 (no lone pair) is what shape
linear
a molecule such as H2O (lone pairs) has what shape
V-shaped planar
a molecule such as NH3 (lone pairs) has what shape
pyramidal
what is an ionic bond
force of attraction between oppositely charged ions in a compound
hydrogen bonds
dipole-dipole attractions between molecules in which hydrogen atoms are bonded to nitrogen, oxygen or fluorine. the hydrogen atom carries a partial positive charge and is attracted to the electronegative atom in another molecule. thus, the hydrogen bond acts as a bridge between two electronegative atoms in separate molecules.
dipole-dipole forces
forces of attraction between the negative pole of one polar molecule to the positive pole of another polar molecule
van der Waals
weak attraction forces between molecules resulting in the formation of temporary dipoles
