Bonding Flashcards
(31 cards)
ionic bonding
the electrostatic force of attraction between opositely charged ionsbformed by electron transfer
do metal atoms lose or gain electrons
lose
covalent bond
a shared pair of electrons
dative covalent bond
the shared pair of electrons in a bond comes from one atom
metallic bonding
the electrostatic force of attraction between positive metal ions and delocalised electrons
factors that affect metallic bonding
- number of protons- more protons=stronger bond
- number of delocalised electrons per atom- more delocalised electrons=stronger bond
- size of ion- smaller ion=smaller bond
ionic bonding properties
•high boiling points- strong electrostatic forces
•good solubility in water
•poor conductivity when solid- ions can’t move
•good conductivity when molten
molecular (simple covalent) bonding properties
•low melting and boiling points -weak intermolecular forces
•poor solubility in water
•poor conductivity when solid- no ions to conduct and electrons are localised
•poor conductivity when molten
macromolecular (covalent) bonding properties
•high bpt and mpt- many strong covalent bonds
•insoluble in water
•poor conductivity apart from graphite
metallic bonding properties
•high mpt and bpt- strong electrostatic forces
•insoluble in water
•good conductivity- delocalised electrons
trigonal planar
3 bonding pairs
bond angle- 120
examples- BF3, NO3
linear
2 bonding pairs
bond angle-180
examples- CO2,HCN
tetrahedral
4 bonding pairs
bond angle-109.5
examples- SiCl4, SO4²‐
trigonal pyramidal
3 bonding pairs, 1 lone pair
bond angle-107
examples- NCl3, PF3
bent
2 bonding pairs, 2 lone pairs
bond angle- 104.5
examples-OCl2, H2S
trigonal bipyrimidal
5 bonding pairs
bond angle- 120, 90
example- PCl5
octahedral
6 bonding pairs
bond angle-90
example- SF6
do lone pairs or bonding pairs repel more
lone pairs
electronegativity
the tendency of an atom in a covalent bond to attract electrons towards itself
what’s the most electronegative element
flourine
factors affecting electronegativity
•increases across a period as number of protons increases and atomic radius decreases
•decreases down a group as distance between nucleus and outer electrons increase and shielding increases
what type of bonding do compounds with small or none electronegativity have
pure covalent
what type of bonding do compounds with a large electronegativity have
ionic
when does a permanent dipole form
when the elements in the bond have different electronegativities