Metallic bond - found in pure metals with single element
electrons are "loosely held" - swarm of electrons are delocalized
(electron cloud)
typically forms between elements that have similar, low electronegativity values
This type of bond results in:
good electrical conductivity
malleable, ductile, sectile behavior
- "glide planes" are established when atoms are all the same sizeNote: an alloy is a mixture of metals.
Difference in atom sizes destroys glide planes
resulting in a material with increased strength and different
properties.
relatively high density material
- because of close packing arrangement of atoms -"densest in
nature" - 12 fold coordination
Covalent bond - "sharing" of electrons, very strong, can be
polar
typically forms between elements with small differences in electronegativity values
graphite: 3 sigma bonds & one pi bond, sp2 hybridization
van der Waal bonds between sheets are very weak
(results in a perfect cleavage, greasy feel, etc.)
Ionic bond - "transfer" of electrons, creates positive and negative ions
bond is a result of electrostatic charges between unlike charges
typically forms between elements with large differences in electronegativity values
Note: 80-90% of minerals have predominately ionic bonds
Polar bond - partial positive and negative charges on the
ends due to asymmetric charges on atoms
Hydrogen bond - the attraction of the H-side of a water
molecule to the negative side of another water molecule
