Bonding 3

Cubic, tetragonal, hexagonal, rhombohedral, orthorhombic, monoclinic, triclinic

Cell edges: a = b = c Cell angles: alpha = beta = gamma = 90 degrees

Cell edges: a = b x= c Cell angles: alpha = beta = gamma = 90 degrees

Cell edges: a = b = c x= d Cell angles: alpha = beta = gamma = 120 degrees The edge d is perpendicular to the plane described by a, b, and c

Cell edges: a = b = c Cell angles: alpha = beta = gamma x= 90 degrees

Cell edges: a x= b x= c Cell angles: alpha = beta = gamma = 90 degrees

Cell edges: a x= b x= c Cell angles: alpha = gamma = 90 degrees, beta x= 90 degrees

Cell edges: a x= BCM = c Cell angles: alpha x= beta x= gamma

Contains only atoms at the corners

Contains atoms at the corners as well as at the center of the unit cell

Contains atoms at its corners and in the center of each face

Ionic solids Covalent solids Molecular solids Metallic solids

Made of (+) & (-) ions arranged in regular arrays; each job is surrounded by ions of the opposite charge Hard brittle, and have high melting and boiling points; poor conductors of electricity

Made of atoms held together by very strong covalent bonds; very hard and high melting points; usually poor conductors of heat and electricity

Made of neutral atoms; held together by dipole forces or dispersion forces; soft and poor conductors of heat and electricity

Are made of one closely packed metal element; free valence e- circulate soured metallic cations making them goof electricity and heat conductors; high melting points

When in some substances, the atoms are packed together as closely as possible

Void created four spheres (3 in the 1st and 1 above) create a regular tetrahedron

Six spheres (3 in 1st layer and 3 in 2nd layer with layers offset by 60 degrees)

Between 3 adjacent spheres in the same layer

Triangular< tetrahedral< octahedral

When sphere of 3rd layer lie directly above spheres of 1st layer

There are N O-holes and 2N T-holes

L = 2r V = L^3 = 8r^3