Periodicity

The regular periodic variation of properties with atomic number and position in the Periodic Table

The breaking up of a chemical substance with heat into at least 2 chemical substances

A reaction in which a more reactive element displaces a less reactive element from an aqueous solution of the latter’s ions

Oxidation and reduction of the same element in a redox reaction

It decreases

It increases

The outer electron is further away from the nucleus and is shielded by electrons in more inner shells so the electrostatic attraction to the nucleus decreases

The number of protons in the nucleus increases and the outer electron is in the same shell, with similar shielding, so electrostatic attraction to the nucleus increases

IE of group 3 is lower than group 2 as the outer electron is in a p-orbital which is higher in energy so evidence for sub-shells IE of group 6 is lower than group 5 as the outer electron has paired up with another electron in a p-orbital so these repel each other and evidence for spin pairing in atomic orbitals

The Bohr model of the atom

Diamond Graphite Graphene

Tetrahedral structure Poor electrical conductivity as no delocalised electrons as all outer shell electrons are used for covalent bonds Hard as tetrahedral shape allows external forces to be spread throughout lattice

Strong hexagonal layer structure but weak van der Waals’ forces between layers Good electrical conductivity as there are delocalised electrons between layers Soft as bonding within each layer is strong but weak forces between layers allow layers to slide easily

Essentially a single layer of carbon in the from of graphite Good electrical conductivity Outstanding mechanical strength with respect to its thinness

1) Strong electrostatic attraction between cations and delocalised electrons 2) Can conduct electricity due to delocalised electrons even in solid state 3) High melting and boiling points as attraction strong as high temps are needed to break these bonds 4) Ductile (can be drawn or stretched) and malleable (can be hammered into shape) 5) This is because of delocalised electrons as they can move which allows atoms or layers to slide past each other

1) Strong covalent bonds between atoms 2) These bonds are throughout the structure 3) High melting and boiling as high temperatures needed to break strong covalent bonds 4) Cannot conduct electricity as no free charged particles except in graphite (and graphene) - electrons are localised 5) Insoluble in both polar and non-polar solvents because covalent bonds are too strong to be broken down by either polar or non-polar solvents 6) Silicon is a metalloid and has a limited number of delocalised electrons that can move through the structure, giving a low conductivity

Metallic, giant metallic and strong forces between cations and electrons

Covalent, giant covalent and strong forces between atoms

van der Waals’ forces, simple molecular and weak forces between molecules

General increase in melting points as difference in ionic charge increases

Sharp decrease in melting point as from giant structures to simple molecular and strong forces to weak intermolecular forces

Comparatively low melting points