ionic bonding Flashcards
what is an ionic bond
an electrostatic attraction between oppositely charged positive cations and negative anions. it is usually formed by electron transfer from a metal atom to a non metal.
3 features of ionic compounds
very high melting and boiling points
soluble in polar solvents (eg water)
only conduct electricity when molten or aqueous
why do ionic compounds have such high melting/boiling points
it takes a great deal of energy to overcome the strong electrostatic forces of attraction, this can only be achieved at high temperatures
what two features make attraction harder to overcome
charge
size
……. charge is harder to overcome
higher
…….. size is harder to overcome
smaller
why do atoms change size when they become ions
the electron cloud becomes smaller or bigger depending on loss or gain of electrons
why can many ionic compounds dissolve in water
water molecules surround the ions and this can overcome the electrostatic attraction between the ions
as charge on the ions increases how does this affect solubility
decreases
what are isoelectronic ions
those having the same electron configuration
what does increasing proton number do to the size of the ion
smaller as they hold the electrons more tightly
what physical properties depend on the strength of the ionic bond
melting and boiling point
negative ions known as
anions (attracted to the anode)
positive ions known as
cations (attracted to the cathode)
charge and colour of copper II ions
2+
blue
