Ch3 Structure and bonding Flashcards
Covalent bond
bond between two non-metals
share pair of electrons
Ionic bonds
electrostatic attraction between metal + non-metal
electrons in outer shell is transferred
5 Ionic compound properties
- held together by strong electrostatic force of attraction between oppositely charged ions
- forces acting in all directions
- lots of energy are needed to overcome strong bonds - high mpt and bpt
- lattice- regular arrangement
- conducts electricity only when molten or dissolved in water- ions are free to carry charge
4 simple covalent molecule properties
weak intermolecular forces
low mpt and bpt
doesn’t conduct electricity
strong bonds between the atoms
Giant covalent structures examples
diamond
graphite
silicon dioxide
4 properties of metallic structure
- lattice
- high mpt+bpt
- lots of energy needed to overcome - good conductors
- sea of delocalised electrons carry charge - soft and malleable
- layers slides over one another
metallic bond
electrostatic attraction between metal + metal
alloys
metal + other element
hard and stronger than normal element
- new element distorts layers so they cant slide
limitations of simple particle model
no forces are shown
all particles are represented as
spheres
the spheres are solid
Polymers
long chain of repeating units strong covalent bond large molecules solid at room temperature - relatively strong intermolecular forces
Giant covalent structure properties
high mpt
- lots of energy needed to overcome strong covalent bonds
Diamond
carbon atoms form 4 covalent bond tetrahedron - very hard doesn't conduct high mpt
Graphite
carbon atoms form 3 covalent bonds layers of hexagonal rings - can slide over on another high mpt conducts - delocalised electrons allow flow of charge
Graphene
separated sheet of graphite strong and light high mpt conducts electricity - delocalised electron
Fullerenes
molecules of carbon atoms with hollow shapes
example is buckminsterfullerene
