bonding

Created by

Julia

Cards (40)

what is ionic bonding  
strong electrostatic forces of attraction between oppositley charged ions held in a lattice
give an example of an ionically bonded substance
NaCl(sodium chloride- salt)
how high are ionically bonded substances bp and mp why
high- takes lots of energy to break strong electrostatic forces of attraction between oppositely charged ions
do ionic compounds conduct electricity why
yes, when molten or in a solution as the ions are free to move and carry charge ( don't when solid)
what is simplest molecular covalent bonding
strong covalent bonds between atoms, weak van der waals forces of attraction between molecules
are there any lone electrons in simples covalent bonding
no they are all involved in bonding
can simple molecular covalent molecules conduct electricity why
no- all electrons are used in bonding and aren't free to move
do simple molecular substances have high/low mpt and bpt why
low- weak van der waals forces of attractions between molecules that don't take much energy to overcome( these are overcome rather than covalent bonds)
describe macromolecular covalent bonds
lattice of many atoms held together by strong covalent bonds
do substances with macromolecular covalent bonds have high/low mpt and bpts why?
high as it takes a lot of energy to overcome many strong covalent bonds
do substances with macromolecular covalent bonds conduct electricity  
most don't as all electrons are used in bonding
draw and describe structure of diamond
https://www.google.com/search?sca_esv=3adfed459a349879&rlz=1CAXBKO_enGB1076&q=draw+and+describe+structure+of+diamond&tbm=isch&source=lnms&sa=X&ved=2ahUKEwiVltap4ryEAxUOT0EAHQg2Bn4Q0pQJegQIEBAB&biw=768&bih=730&dpr=1.25&safe=active&ssui=on#imgrc=7goy2-l7Nv4CVM
draw and describe structure of graphite
similar to diamond- macromolecular covalent- but each C is only bonded to 3 others so it is in layers
weak van der waals forces of attraction between layers mean they can side over each other - soft, slippery
one electron from each carbon is delocalised and can carry charge- conducts electricity
describe and draw metallic bonding
lattice of positive metal ions strongly attracted to a sea of delocalised electrons layers can slide over each other- malleable
do metallic compounds have high/low bpt and mpts why
high as strong forces of attraction between positive metal ions and negatively charged sea of delocalised electrons
do metallic compounds conduct electricity why  
yes as delocalised electrons can move throughout the metal to carry charge
how does the strength of metallic bonds change across the periodic table why 
increases- higher melting and boiling points stronger higher charge on metal ions
more delocalised electrons per ion
strong force of attraction between them
define electronegativity
the ability of an atom to attract the pair of electrons( electron density) in a covalent bond
what affects electronegativity
nuclear charge
atomic radius
electron shielding
what is the most electronegative element
fluorine-(4.0 on pauling's scale|) - largest nuclear charge for its electrons shielding small atomic radius
how do you get a nonpolar bond
both bonding elements have the same electronegativities
when do you get a polar bond
bonding atoms have different electronegativities
what is a strong type of inter- molecular force
hydrogen bonding
what is the weakest type of inter molecular force
van der waals forces
describe van der waals forces of attraction
temporary dipoles are created by the random movement of electrons- induces dipole in neighbouring molecule - temporary induced dipole- dipole aka van der waals forces of attraction
are van der waals forces greater in smaller or larger molecules
larger- more electrons
describe permanent dipole-dipole attraction
some molecules with polar bonds have permanent dipoles- forces of attraction between those dipoles and those of neighbouring molecules
what conditions are needed for hydrogen bonding to occur
O-H, N-H, or F-H bond
lone pair of electrons on O,F,N
because O,N,F are highly electronegative , H nucleus is left exposed
strong forces of attraction between H nucleus and lone pair of electrons on O,N,F
draw a diagram of hydrogen bonding
https://docs.google.com/document/d/16kPXIfEyHwGSQUFJXvCj3veRcybJ7Kbb2ob5TkkCciQ/edit
why is ice less dense than liquid water
in liquid hydrogen bonds constantly break and reform as molecules move about
in ice, the hydrogen bonds hold the molecules in a fixed position this makes them slightly further apart than in liquid water
what is a dative/ co-ordinate covalent bond when it is formed
formed when an electron deficient atom/ ion accepts a lone pair electrons from an atom/ion with a lone pair of electrons( not used in bonding)
draw the formation of a dative covalent bond in ammonia
https://docs.google.com/document/d/16kPXIfEyHwGSQUFJXvCj3veRcybJ7Kbb2ob5TkkCciQ/edit
what does the shape of molecules depend on
number of electrons in the valence shell of the central atom
number of these electrons which are in bonded or lone pairs
what does electron pair repulsion theory state
the electron pairs will take up positions as far away from each other as possible to minimise the repulsive forces between them
which experience the most repulsion 1) lone pair lone pair 2) lone pair bonded pair 3) bonded pair bonded pair
lp-lp repulsion strongest
lp-bp repulsion middle
bp-bp repulsion weakest
what is the shape diagram and bond angle in a shape with 2 bonded pairs and 0 lone pairs
linear 180
o-o-o
what is the shape diagram and bond angle in a shape with 3 bonding pairs and 0 lone pairs
trigonal planar 120
o
|
o
/ \
o o
and bond angle in a shape with 4 bonded pairs and 0 lone pairs
tetrahedral 109.5
what is the shape diagram and bond angle in a shape with 5 bonded pairs and 0 lone pairs
trigonal bypyramid
90 and 120
and bond angle in a shape with 6 bonded pairs and 0 lone pairs
octahedral 90