chem structure and bonding

Stability

How resistant an atom or compound is to a chemical change

Chemical bond

A strong electrostatic force of attraction between two atoms or ions

Elements in ionic bond

Metal give electrons to non metal

Ionic compound

Giant lattice of oppositely charged ions held together by strong electrostatic forces

Ionic bonding properties

-solid at room temp because strong ionic bonds

-oppositely charged ions pack tightly and rigidly and form crystal lattice which is hard to break

-high melting point over 2000

-conducts electricity when molten or aqueous

Why high melting point for ionic bonds

Strong electrostatic attraction

Why ionic bond conduct electricity when not solid

Ions free to move

Brittle

Breaks with little force because repulsion between ions

Elements in Metallic bonding

Metals

Why metal conduct electricity

Sea of delocalised electrons move and carry charge

Ductile

Material can be stretched without breaking

Why metals ductile

Delocalised electrons move, slide over eachother and hold metal together

Why metals malleable

electrons slide over eachother

Alloy

mixture of metal blended with other elements

Why alloys used in construction

strong, ions different sizes, cannot slide over eachother

Elements in covalent bonding

Non metal share electrons with non metal

Carbon dioxide molecule

-4 shared pairs of electrons & covalent bonds

-stable

-full valence shells

simple covalent molecule eg

H2O(water), O2(oxygen), CO2(carbon dioxide)

Simple covalent properties

-low melting point

-no electric charge

-doesnt conduct electricity

Intermolecular forces

Weak forces of attraction between molecules which dont require energy

Allotropes

Different structural forms of same element, can be different properties

Giant covalent properties

-Adjacent atoms joined

-strong

-usually arranged in regular lattice

-strong covalent bonds, no intermolecular forces

Giant covalent molecule eg

Diamond, graphite, graphene, fullerene

Nanoparticle

A small particle that ranges between 1 to 100 nanometres

Diamond properties

-4 strong bonds to other carbon

-high melting point

-insoluble

Graphite

-3 carbon atoms

-1 delocalised electron, conducts electricity and heat

-weak forces between layers that can slide over eachother

Graphene

-single layer of carbon atoms

-hexagon pattern

-2D

-use: fast computer chips, solar panels, flexible phone screens

-high melting point

-conducts electricity

Fullerene

-shape of hollow spheres, tubes or cages

-separate molecules instead of giant structure

-use:drug delivery in body, lubricants

-lightweight

-conducts electricity

-carries other molecules

-low melting and boiling point

Buckminsterfullerene

C60

Nanotubes

-type of fullerene

-cylinder

-strong and lightweight

-use:nano tech, tiny wires

-big surface area

-catalyst support

-high tensile strength

-conducts electricity and heat

Dot and cross limitation

No size indication

Ball and stick limitation

Too widely spaced

Space filling limitation

Wrong size