Chemical bonding Flashcards
Ionic bonding
transfer of electrons from metallic atoms to non-metallic atoms
- metallic atom becomes a cation ; loses electrons
- non metallic atom becomes an anion ; gains electrons
Properties of ionic compounds
-oppositely charged ions
- held together by strong electrostatic force of attraction
- normally hard solids
- high MP & BP; high lattice energy
- non-conductors of electricity in solid state
- good conductors in molten & aqueous states ; ions become mobile
- good electrolytes
- do not dissolve in non-polar organic solvents
-
Non-polar organic solvents
- benzene
- toluene
Covalent bonding
sharing of electrons between 2 atoms of non-metals
- ions not formed
- molecules formed
Properties of covalent bonding
- consist of molecules ; not ions
- normally gases / volatile liquids
- low MP & BP
- non-conductors of electricity
- dissolve in non-polar organic solvents
Structures of solid materials
1) Metallic
2) Giant ionic
3) Simple molecular
4) Giant molecular
Metallic structure
- metallic bonding
- delocalised electrons form a sea of electrons revolving around the positive ions
Sea of electrons causes
- conduction of electricity
- shininess
- tensile strength
What makes metals malleable
when a force is applied, ions slide over each other & the electrons move to keep the ions in a new position
Giant molecular structures
- allotropes of carbon
- silicon
- silica
Allotropes of carbon
- diamond
- graphite
Properties of diamond
- one of the hardest substances ever known
- transparent & sparkling when pure
- non-conductor of electricity
- very high MP & BP
Uses of diamond
- cutting glasses
- tips of drills
- jewels
Properties of graphite
- opaque
- slightly shiny
- soft & slippery
- high MP & BP
- can conduct electricity
Uses of graphite
- lead in pencils
- electrodes in cells
- lubricant in engines of aeroplanes
