Bonding Flashcards
Electronegativity
The power of an atom to attract a pair of electrons towards itself in a covalent bond
How do Van der waals forces work (induced)
Instantaneous movement of electrons in atom causes one side of atom become electron dense (slight negative) so opposite side of atom becomes slightly positive
The electron dense side repels the electrons of another atom which also induces a dipole in the other atom
They are now attracted by van der waals forces
Properties of van der waals forces
- Weak (easily broken) as force is temporary
- Happens in all molecules/atoms bc they all contain electrons
- more electrons means the stronger the vdw forces
How do permanent dipole-dipole forces work
ionic bond
electrostatic forces of attraction between oppositely charged ions
arranged in a regular lattice structure
covalent bond
a shared pair of electrons between two atoms
coordinate (dative) bond
type of covalent bond
where the shared pair of electrons are donated by only one of the atoms
metallic bonding
electrostatic forces of attraction between positive metal ions and negative delocalised electrons
intermolecular forces definition
the forces of attractions within molecules
hydrogen bonding
a type of intermolecular force
between a hydrogen and one of FON (fluorine, oxygen, and nitrogen)
to another molecule with a lone pair
two bond pairs
no lone pairs
linear shape
180 degrees
three bond pairs
no lone pairs
trigonal planar
120 degrees
four bond pairs
no lone pairs
tetrahedral
109.5 degrees
three bond
one lone pair
trigonal pyramidal
107 degrees
two bond
two lone pairs
bent
104.5 degrees
5 bond pairs
no lone
trigonal bipyramidal
90 and 120 degrees
6 bond pairs
no lone
octahedral
90 degrees
4 bond
2 lone pairs
square planar
90 degrees
vsepr theory
bond and lone pairs repel as far as possible to minimise repulsion forces
lone pairs repel stronger than bond pairs
if lone pair is present, bond angle decreases
properties of metallic structures
high mp/bp due to strong efa between opp charges
electrical conductor due to delocalised electrons
insoluble in water
malleable as same size atoms layers slide over e o
factors affecting strength of metallic bond
higher charge of metal ion = stronger
more delocalised e = stronger
smaller metal ions = stronger
properties of ionic compounds
high mp/bp due to strong efa
electrical conductors when molten/dissolved
soluble in water
properties of simple molecular compounds
low mp/bp due to weak intermolecular forces
do not conduct electricity
usually insoluble in water (unless polar)
properties of macromolecular compounds
high mp/bp = strong im forces
only graphite conducts electricity as there are delocalised electrons between layers
