Topic 4 - Bonding Flashcards
Definition of Electronegativity
The ability of an atom to attract the bonding electron pair in a covalent bond to itself.
Increase across periods
Decrease down the group
F fluorine has the highest value
Formation of ionic bond in terms of electronegativity
Elements with low value (G1,2) will form ionic bonds with atoms of high electronegativity (G16,17)
Formation of covalent bond in terms of electronegativity
With moderate to high electronegativity (G14-17), tend to form covalent bond.
Formation of metallic bonds in terms of electronegativity
Elements with low electronegativity (metals) can join together by metallic bonding forming alloys.
The type of bond if difference in electronegativity is 0-0.4
Non polar covalent bonds
The type of bond if difference in electronegativity is 0.5-1.7
Polar covalent
The type of bond if difference in electronegativity is greater or equal to 1.8
Ionic bonds
Intermolecular forces - name three types
Between covalently bonded molecules
1, London dispersion force
2, dipole-dipole
3, hydrogen bonds (FON)
Intramolecular force - name three
Covalent bond within the molecule
C=C strong double bond
1, ionic
2, covalent
3, metallic
Generally ionic bonds are formed from
Metal - metal
Generally covalent bonds are formed from
Non metal - non metal
Who lose or gain electron in ionic bond reference electronegativity
Within Ionic bonded molecule,
Low electronegativity lose e to the higher one
ionic bonded molecule - structure
crystal lattice structure held by electrostatics attraction
Physical properties of ionic compounds
1, high MP
2, brittle - if like charges ions line up, repulsion split the crystal
3, electrical (conductivity) - not solid, yes when molten or in aq solution
Free mobile electrons and conduct electricity
4, soluble in polar (water) not in non polar solution
