Electrons and Bonding Flashcards
why does 4s fill before 3d
the 3d subshell is at a higher energy level than the 4s subshell
ionic bonding
electrostatic force of attraction between positively (cations) and negatively charged ions (anions)
ionic bonding diagrams
separate ions showing movement of electrons
giant ionic lattice
each ion attracts oppositely charged ions in all directions
property of ionic compounds at room temp
- solids at room temperature because insufficient energy to overcome strong electrostatic forces of attraction between ions
why does melting point increase (ionic compounds)
melting point is higher for lattices containing ions with greater ionic charges as there is stronger attraction between ions
melting points are higher for smaller ions as they have stronger nuclear attraction
solubility of ionic compounds
ionic compounds dissolve in polar solvents (water) as water surrounds each ion in solution
in some ionic compounds, ionic attraction may be too strong for water to be able to break down.
conductivity of ionic compounds
solid state: doesnt conduct electricity ad ions are fixed in position so no mobile charge carriers
liquid or aqeous: solid ionic lattice broken down and ions are free to move as mobile charge carriers
3 properties of ionic compounds
high melting and boiling points
dissolve in polar solvents
conduct electricity as liquids
covalent bonding
strong electrostatic force of attraction between a shared pair of electrons and the nuclei of bonded atoms (non metallic compounds
covalent bonding diagrams
show overlap of orbitals, combine two atoms
difference in electron movement in ionic bond and covalent bond formation
in covalent bonding electrons are shared
in ionic bonding bonding electrons are transferred
dative covalent bond
covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms onlye.g. NH4+ (Arrow points to where electrons shared)
metallic bonding
electrostatic force of attraction between positive metal ion and delocalised electrons
