Bonding and Structure Flashcards
definition of a covalent bond
the electrostatic attraction between two nuclei and a shared pair of electrons
definition of ionic bond
the electrostatic attraction between two ions of opposite charge
definition of metallic bond
the electrostatic attraction between positivey charged metal ions and delocalised electrons
what is an ion
a charged particle that has either lost of gained electrons, resulting in a charge and a stable electronic structure
what is electrostatic attraction
attraction between positively charged and negatively charged particles
what is an ionic lattice
the arrangement of ions into a large structure, consisting of alternating positive ions and negative ions
what are delocalised electrons
electrons that are not tied to a particular atom, but are free to move throughout the structure
what is a metallic lattice
a giant, regular, repeating structure of positive metal ions existing in a sea of delocalised electrons
what is a crystal structure
a substance which has a type of structure
what is a dative bond / co ordinate bond
a covalent bond where the shared electron pair comes from only one participating atom
what is a lone pair
a pair of electrons on an atoms outer shell that is not being used in a bond
what is electronegativity
the tendency of an element to attract a shared pair of electrons to itself within a covalent bond
what is a polar bond
a bond formed between atoms with differing electronegativities
what is a permanent dipole
occurs in a molecule which is asymmetric and has one side which is more positive and one which is more negative
what are pd-pd interactions
interactions that occur between molecules that have permanent dipoles
what are london forces
instantaneous dipole induced dipole forces arising from random movement of electrons
how do london forces arise
- random movement of electrons
- more electrons = greater london forces
how do pd-pd forces arise
how do hydrogen bonds arise
what is the weakest IMF
london forces
what is the strongest IMF
hydrogen bonds
what are hydrogen bonds
molecules that contain hydrogen atoms directly bonded to N O or F atom will form these bonds with other molecules that contains H directly bonded to N O or F
what are isoelectronic species
species with the same electronic figure
what is the name and bond angle of a molecule with 2 bonding pairs, no lone pairs
linear, 180
what is the name and bond angle of a molecule with 3 bonding pairs, no lone pairs
trigonal planar, 120
what is the name and bond angle of a molecule with 2 bonding pairs, 1 lone pair
bent/ V shaped, 117.5
what is the name and bond angle of a molecule with 4 bonding pairs, no lone pairs
tetrahedral, 109.5
what is the name and bond angle of a molecule with 3 bonding pairs, 1 lone pair
trigonal pyramidal, 107
what is the name and bond angle of a molecule with 2 bonding pairs, 2 lone pairs
bent/ v shaped, 104.5
what is the name and bond angle of a molecule with 5 bonding pairs, no lone pairs
trigonal bipyramidal, 120 & 90
what is the name and bond angle of a molecule with 3 bonding pairs, 2 lone pairs
T shaped, 175, 85
what is the name and bond angle of a molecule with 4 bonding pairs, 1 lone pair
see-saw, 117.5 equatorial & 87.5 axial
what is the name and bond angle of a molecule with 6 bonding pairs, no lone pairs
octahedral, 90
what is the name and bond angle of a molecule with 5 bonding pairs, 1 lone pair
square pyramidal, 90 equatorial & 87.5 axial
what is the name and bond angle of a molecule with 4 bonding pairs, 2 lone pairs
square planar, 180 & 90
what’s the general structure of an answer when explaining why a molecule has that bond shape and that bond angle
there are _ electron pairs around the central atom: _ bonding pairs and _ lone pairs
All electron pairs spread out as far as possible to minimise repulsion
Lone pairs repel more than bonding pairs
So the shape is _ and the angle is _
