BECE MODULE 2

• graphite is a metal; diamond is an insulator and Buckminster fullerence is a superconductor
• Crystalline materials are solids with an atomic structure based on a regular repeated pattern.
• Crystal Lattices a symmetrical three-dimensional structural arrangements of atoms, ions or molecules (constituent particle) inside a crystalline solid points.
• Three Types of Solids: Crystalline

  Amorphous Solids Polycrystalline
• Polycrystalline solids, these are consisting of many small crystals(“grains”)
• Amorphous Solids- it is a type of matter that lacks regular long-range order
• Crystal Lattices- It is an infinite array of points in space.
• Crystal Structure- This can be obtained by attaching atoms groups of atoms or molecules which are called basis to the lattice sides of the lattice point.
• Lattice- A regular repeated three-dimensional arrangement of atoms, ions, or molecules in a metal or other crystalline solid.
• Cubic Lattices- The simplest three-dimensional lattice is one in which the unit cell is a cubic volume.
• Simple cubic(sc) - has an atom located at each corner of the unit cell
• Body-Centered cubic (bcc) - lattice has an additional atom at the center of the cube.
• Face-centered cubic (fcc) - unit cell has atoms at the eight corners and centered on the six faces
• Diamond Lattice - The characteristics of Si(Silicon), Ge(Germanium), and C(Carbon) in a way of diamond form.
• Single Lattice - Has a periodic atomic structure across its whole volume.
• Amorphous Solids- Made up of randomly oriented atoms, ions, or molecules that do not form defined patterns or lattice structures.
• Unit Cell in 2D- The smallest component of the crystal
• Binding(cohesive) energy of the crystal- energy of the crystal is lower than that of the free atoms by an amount equal to the energy required to pull the crystal apart into a set of free atoms.
• Ionic bonding - is the electrostatic force of attraction between positively and negatively charged ions(between non-metals and metals).
• Covalent Bonding - formed when the atoms share the outer shell electrons rather than by electron transfer
• Metallic Bonding- is found in metal elements.This is the electrostatic force of attraction between positively charged ions and delocalized outer electrons.
• Hydrogen Bonding- A hydrogen atom, having one electron, can be covalently bonded to only one atom.