Topic 2 Flashcards
Isotopes
Different atoms of the same same element
Same photon electron no
Diff. neutron no
Relative Atomic Mass
Weighted average of relative isotopic masses on 12 6 C=12 scale
Ionic Bond
Strong non-directional electrostatic force between oppositely charged ions
Transfer of electrons
Covalent bond
Strong directional electrostatic force
Attraction between electrons (-ve) and nuclei (+ve)
Sharing of electrons
Dative Covalent Bond
Share electrons contributed by one atom
Metallic Bond
Attractions bewteen Delocalized electrons and atoms
Electrostatic attraction
Structures Types
Molecular Structures:
Simple Molecular
Macromolecular - polymer
Giant Structures:
Giant Ionic - ionic compounds
Giant Covalent - Diamond, SiO2 Graphite Silicon
Giant Metallic - all metals
Why can graphite conduct electricity
It has delocalized electrons
Why is graphite soft
Layers held tgt by weak van der Waal’s force
Slide over each other
Ionic compound
Physical properties
Solid - Crystalline Hard but Brittle - same charge comes tgt repulsion High mp bp Soluble in water Conduct electricity when molten or aq
Giant metallic structure
Properties
Malleable and Ductile - slide over, non-directional force does not break
Conduct heat and electricity
Alkali metals Alkaline earth metals Halogens Bp mp Reactivity Down the gp
Gp 1
Decreass
Increase
Gp 2
Decrease??
Increase
Gp 7
Increase
Decrease
Simple mokecular structure
Giant ionic
Lattice structure different
Simple molecular
8 vertix 6 faces - 14
Giant ionic
Na vertix + faces - 14
Cl on sides and middle - 13
Cs in middle -1
Cl at vertix - 8
