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What are the 6 types of substances
molecule,
covalent network 2D AND 3D
Ionic
Metallic
Non polar
Polar
Melting points and Boiling points
For a substance to melt or boil sufficient amount of energy has to overcome the forces between the particle and seperate them, so if the force between particles are to strong a lot of energy is required which means a high melting point and is the forces are weak then low melting point.
Electrical conductivity
for a substance to conduct electricity it has freely moving particles like ions or electrons
Structure of metallic compounds
In metal atoms they are together in 3D lattice through metallic bonding the bonding is non-directional as the valance electrons are delocalised meaning freely moving and therefore attracted to positive nuclei of the neighboring atoms.
Structure of ionic compounds
the positive and negative ions are arranged in a 3D lattice. The cations and anions which are held together by an electrostatic attraction between opposites charged ions this attraction is strong and called ionic bonding.
Malleable/ ductility
metals can be bent,hammered,stretched, pulled into wires due to non-directional forces of metallic bonding but when an external force is applied layers of metallic atoms slide over each other without breaking metallic bonds
Brittleness
Ionic substance have directional forces so when an external force is applied ions with same charge repel and break the ionic bonds which cause solid to crack
Conductivity
to conduct electricity freely charged moving particles are needed
Metallic and ionic compounds
they are hard as their attractive forces are strong and closely packed atoms or ions bonding
Metals bonding
They lose electrons and form positive ions
non-metals bonding
gain electrons and form negative ions
Ionic Bonding
Transfer of electrons
Convalent bonding
sharing of electrons and non metals
structure of molecular substance
strong covalent bonding exists between atoms within the molecule but weak intermolecular forces exist between molecules
Allotropes
different physical forms in which an element can exist
Structure of 2D convalent network
in graphite, each carbon is convalently bonded to three other carbon atoms in a 2D arrangement forming layers the remaining valence electrons is delocalised and free to move through layers those are held together by weak van der waal forces.
Molecular substance traits
the molecule are weak so require small amount of energy to break so low melt and boil point
No freely moving particles so no conduct electricity
Polar molecules dissolve in polar solvent like water and non polar molecules dissolve in non polar solavent
