Types of bonding

Giant ionic lattice

Alternating charged ions

Very strong electrostatic forces

High melting/ boiling point (ionic)

Due to strong electrostatic forces that need lots of heat energy to break bonds

Cannot conduct as a solid (ionic)

Tightly packed and held together with bonds

Can conduct when molten (ionic)

Ions can now move and carry an electric charge

Low melting/boiling points (covalent)

Atoms in each molecule held together by strong covalent bonds, but very weak intermolecular forces between them.

As temp increases vibrations break intermolecular forces - do not require much energy to break

Larger alkanes

Higher boiling points due to more intermolecular forces needed to be broken

Do not conduct (covalent)

Do not have overall electric charge

Giant covalent substances

Solid at room temp due to high melting/ boiling points

Diamonds

Surrounded by 4 covalent bonds to carbon in tetrahedral shape - very hard material

High boiling points in order to overcome many covalent bonds

Unable to conduct electricity

Silicon dioxide

Same features as diamond, but oxygen and silicon atoms.

Graphite

1 carbon ion covalently bonded to 3 others

Properties of graphite

Soft and slippery - weak intermolecular forces between la

High m/b points - lots of covalent bonds

Good conductor of heat and electricity - delocalised electrons free to move throughout structure

Graphene

Single layer of graphite

One atom thick

Can conduct electricity

High m/b points

Buckminsterfullerene

60 carbon atoms arranged in a sphere

Used to carry and deliver pharmaceuticals to body

Used as lubricants and catalysts

Lower b/m point that other allotropes since only IMF need to be overcome.

Carbon nanotubes

Long cylinders with narrow diameter

High tensile strength (stretchy)

Polymers

Made up of identical structures called monomers

High melting point due to the many intermolecular forces that need to be broken

Metallic bonding

Sea of delocalised electrons

Strong electrostatic attraction between electrons and positive ions

Metals

High m/b points due to breaking electrostatic forces of attraction requiring lots of energy

Charged electrons free to carry current around

Layers can slide, allowing metals to be malleable

Alloys

mixture of metals

Different sizes of atoms distort layers in alloy which makes them harder

Nanoparticles

High surface area to volumes ration - only a lil is needed for large s.a.

Danger of being absorbed into cells