Bonding Flashcards
Metallic bonding
- GML
- positive ions in a regular lattice
- delocalised electrons
- stronger metallic bonding when
- smaller ion
- more charge on the ions
- higher forces of electrostatic charge between delocalised electrons and positive ions
Properties of metals
- good conductors of heat and electricity
- strong
- malleable and ductile
- high melting point
Why are metals good conductors
- delocalised electrons are able to move freely thronging the structure
- ions are closely packed and so pass vibrational energy on more effectively
What are metals malleable and ductile
- the layers OF ATOMS slide over each other
- malleable - beat into shape
- ductile - drawn into thin wires
Ionic bonding
- GIL
- one loses electron and one gains an electron creating ions.
- metals are cations, non-metals are anions
- the smaller the ions and the greater charge of the ions, means many strong forces of attraction between positive and negative ions
Properties of ionic compounds
- GIL
- High melting point
- many strong forces of attraction b/w positive and negative ions
- conductivity
- when dissolved in water or molten, ionic compounds conduct electricity so that ions can move and conduct electricity
Ammonium
NH4+
Nitrate
NO3-
Mercury
Hg2(2+)
Cyanide
CN-
Hydroxide
OH-
Peroxide
O2(2-)
Sulphate
SO4(2-)
Carbonate
CO3(2-)
Phosphate
PO4(3-)
Permanganate
MnO4-
Dichromate
Cr2O7(2-)
Acetate
C2H3O2-
Dative covalent bonding
Is a covalent bond in which both electrons come from the same atom
It is drawn with an arrow rather than a —
Covalent bonding
- SCM
- GCL
Potassium vs aluminium
Aluminium
- smaller ion as less shells - higher charge - stronger forces of attraction b/w ion and delocalised electrons
Order of repulsive powers with shapes of molecules
- Lp-lp
- Lp-bp
- Bp-bp
Lp-bp has a greater repulsion than bp-bp
Degree of linear shape
180
Degree of trigonal planar
120
Degree of tetrahedral
109.5
Degree of trigonal bipyramid
120, 90
Degree of octahedral
90
Summary of shapes of molecules
Electronegativity
This is the measure of the tendency of an atom to attract a bonding pair of electron in a covalent bond
What determines electronegativity
- Nuclear charge
- more protons
- stronger attraction between nucleus and BONDING PAIR of electrons - Atomic radius
- closer to the nucleus
- stronger attraction between nucleus and bonding pair of electrons - Shielding
- less shells of electrons between the nucleus and electrons
- less shielding
- stronger attraction between nucleus and bonding pair of electrons
Trend of electronegativity in a period
- increases
- all electrons are the same distance from nucleus
- proton number increasing
- atoms are getting smaller
- shielding is the same
- so stronger attraction between nucleus and 2 electrons in covalent bond
Electronegativity down a group
- decreases
- increase atomic radius
- electrons are further away
- more shells/ more shielding
- reduced force of attraction between nucleus and 2 electrons in covalent bond
Polar bond
- one of the atoms holds the electrons closer to itself in the bond
- one end of the bond will be slightly negative due to the electrons being there
- the other end will be slightly positive due to the electrons not being there
Diff types if imf
Hydrogen
Dipole-Dipole
VDW
Which bonding type do you only mention imf
SCM
Inter MOLECULAR forces - simple covalent MOLECULES
Noble gas boiling points down group
- increases
- more shells
- more shielding
- more electrons, so more vdw forces
Different types of crystal structures
- GIL
- GML
- Macromolecular (GCM)
- Molecular (SCM)
