Bonding Flashcards
what is an ionic bonding
The strong electrostatic force of attraction
between oppositley charged ions
what are ionic crystals
giant lattices of ions, which is the same unit repeated over and over again
why can ionic compounds not conduct electricity when solid
as when they are molten/dissolved
the ions are free to move to carry a charge
why do ionic compounds have a high melting point
as the giant ionic lattices are held in place by electrostatic forces of attractio which require alot of energy to break
why can ionic compounds dissolve in water
as water molecules are polar
so the water molecule pulls ions away from lattice causing it to dissolve
when do molecules form
when two or more atoms bonds together
what is a covalent bond
a shared pair of electrons
what are simple covalent compounds
one with strong covalent bonds holding atoms together
but weak intermolecular forces between molecules
what decides the properties of simple covalent compounds
their intermolecular forces
they have low melting and boiling points
they are electrical insulators
what is a co-ordinate bond
a covalent bond in which one of the atoms provides both of the shared electrons
what bonding and lone pairs of electrons exist as
charge clouds
which is an area where you have a big chance of finding an electron.
what is a dipole
a difference in charge between the two atoms caused by a shift in electron density in the bond
what causes a molecule to have a permanent dipole
if charge is unevenly distributed across the whole molecule
what is a polar molecule
a molecule with a permanent dipole
what is a charge cloud
an area where you have a large chance of finding an electron
outline the structure of ice
When water freezes hydrogen bonds hold the molcules in fixed positions
so they are no longer free to move resulting in a 3D structure that resembles diamond
why is ice less dense than water
molecules are slightly less closely packed than water
so ice is less dense than water
what affect do lone pairs have on bond angles
lone pairs decrease bond angles as
lone pair only attracted by nucleus thus is pulled closer to it than the shared pairs
so repulsion between a lone pair and a bonding pair greater than two bonding pairs do bond angle decreases
