bonding Flashcards
metalic bonding
a lattice of positivly charged ions, cations, sorounded by free/ delocalised elctrons
electrostatic force of attraction between lattice of metal cations and sea off delocalised electrons
characteristics of metalic bonding
high melting and boiling point, because lots of energy needed to break strong electrostaic force of attraction
malleble and ductile, beaten into sheets, pulled in wires.- layers can slide over, can change shape but not break because of electrostatic force of attraction bewteen cations and electrons not broken
hard/ strong= difficult to compreess, and high tensi force
lusturous- electrons form barrier which reflects light
sonorous- reflects sounds/ condicts
conducts heat and energy- 1, electrons vibrate collide with cations and conduct heat// 2, electrons can carry charge
alloys// characteristics
combination/ mixture of 2 or more metals
- harder then pure metal
- less malleble,
- poorer conductors then pure metals
ionic compunds
made of cations which loses an electron and transfer it to an anion which gains the electron.
forms a giant ionic lattice- strong electrostatic force of attraction occurs between the oppositiely charged ions.
ionic compound characteristics
brittle high melting and boiling point soluble in molten and water solutions cant conduct electricity in solid conduct electricity in solutions
polyatomic ions aretate nitrate hydroxide permanganate cyanide sulfate carbonate chromade dichromade ammoniam
CH3OO - OH- MnO4 - CN- SO4 -2 CO3 2- Cr04 2- PO4 3- NH4 1+
covalent bonding
is a bond between shared pairs of electrons,.
electrostatic force of attraction between the nuclei of 2 atoms and 1 or more shared pairs of electrons
some can expand ast 8 electrons- sulfur hexaflurine
dative covalent bonds
covalent bond in which shared electrons contributed by 1 atom
electron repulsion theory
shape of a molecule is determind by the number of electron pairs sorounding the centeral atom
affects melting and boiling point/ hardness and solubility
linear shape
2 bonding pairs, at 180 degrees
trigonal planar
3 bonding pairs, 120 degree angles
tetrahedral
4 bonding pairs at 109.5 degrees
trigonal pyramid
1 lone pair, angles are approx 109.5
v shaped/ bent
2 lone pairs
linear shape/ diatomic
3 lone pairs
lone pairs
more repulsive because greater electron denisty and will repel more bonded pairs, pushing a pair down 2.5 degrees
covalent molecules characteristics
low melting and boiling point
do not conduct electrictiy
giant covalent networks
high melting and boiling point
x conduct elec
very hard
insoluble
alotropes
an alternative structured form of an element
diamond
giant covalent network
carbon bonded to 4 others covalently in tetrahedral shape
hard insulator
high melting because requires large amount of energy to break strong c bonds
x conduct electricity because no free moving charged particles
silcion dioxide
2 silcons covalently bonded to an oxygen tetrahedral shape
graphite
insoluble/ high melting bp
soft used as lube
conducts electrcitiy because 1 unbonded electron freely able to move
dispersion
intermolecular forces,
occurs between all molecules due to constant movement of electrons
very weak
greater surface area- greater area for forces to act across- requires more energy to change state
greater amount of electrons greater temp dipole
dipole dipole
intermolecular force
occurs when there is a differenc in electronegativivty leads to one with greater electroneg having greater pull on other side,
greater electroneg- means delta neg other side delta pos
when 2 dipoles attract- b/w polar molecules
polar
uneven distribution of charge and electrons
NOT POLAR IF WHOLE OUTSIDE IS DELTA POS, TETRAHEDRAL SHAPE
hydrogen bonding
when the hydrogen in bonded to NOF in a molecules expeirence a strong intemolecular force between a lone pair of eleectrons on a NOF
