Bonding- macromolecules

Crystals

crystals are solids whose particles have a regular arrangement of atoms and are  help together by forces of attraction. Bo0nds can be strong intramolecular or weak intermolecular. The strength of the forces affect the physical properties of the crystals

strong forces= high melting points and enthaly of fusion

basic crystal structures are: ionic, metalic, molecular and macromolecular

Ionic crystals

• have strong electrostatic attraction between oppasitely charged ion
• high melting points
• strong electrostatic attraction extrends throughout the whole structure
• lot of energy is required to break inos apart

Metallic crystals

• lattice of posative ions embedded in a sea of delocalised electrons
• attraction of posative to negative extends throughout the structure
• high melting point

Molecular structures

• molecules found in a regular array by intermaolecular forces
• covalent bonds within the molecule holds atom together but do not act between molecules
• intermolecular forces are weak so molecular crysta;s have low melting points
• Iondine: stromg covalent bonds hold iodine atoms together. Iodine molecules have a large number of electrons, van den waals are strong enough to hold the molecules together as a solid.
• van der waalsa re weaker than covalent bonds and this gives iodine its properties
• crystals are soft and easy to break
• low melying point and sublimes readily form gaseous iodine moleculesa
• doesnot conduct electricity, there are no charged particles to carry a charge/ current

Macromolecular crystals

the covalent bonds extend throughout the compound and have typical properties of giant structures held together with strong bonds

diamond and graphite are both made up of carbon. They are allotropes of carbon. They are different materials because atoms are bonded differently. Examples of macromolecular structure

Diamonds

each carbon atom forms 4 single covalent…