ionic bonding

    Cards (18)

    • An ion is an atom or molecule which has gained or lost one or more electrons.
    • Sodium wants to lose an electron as it has one electron in its outer shell and prefers a full outer shell.
    • Chlorine wants to gain an electron as it has seven electrons in its outer shell and prefers a full outer shell.
    • If sodium and chlorine get together, a chemical reaction happens and sodium gives an electron to chlorine, becoming a positive ion and chlorine becomes a negative ion.
    • In a sodium atom, if the outer shell is full, there are no dots or crosses, but with a plus to show that it has a positive charge, a dot and cross diagram is drawn.
    • The charge of a fluorine ion, F-, is represented by a cross, as the shell is full.
    • A bond will be weakest when there is only single charges and the ions are large.
    • A bond will be strongest when there is more charge and the ions are smaller.
    • Chlorine is in group seven, so eight minus seven is one, resulting in Cl-.
    • Polyatomic ions include CO3 2- (carbonate), SO4 2- (sulfate), NO3- (nitrate), and OH- (hydroxide).
    • The strength of an ionic bond depends on the charge of the ions and their size.
    • For the ions of metals, a dot and cross diagram is drawn if the outer shell is full, but if the outer shell is not full, either a dot or a cross can be used to represent the electrons.
    • If the outer shell of a non-metal atom like chlorine is full, no dots or crosses are drawn, but with a plus to show that it has a negative charge, a dot and cross diagram is drawn.
    • Negative ions are called anions, while positive ions are called cations.
    • Ionic compounds have giant structures with millions and millions of positive and negative ions all sticking together when solid.
    • Positive ions, or cations, are named according to the element they come from, for example, Na+ for sodium, Be2+ for beryllium, Al3+ for aluminium.
    • Negative ions, or anions, are named according to the element they come from, for example, Cl- for chlorine, Br- for bromine, I- for iodine.
    • In a dot and cross diagram, if the outer shell is full, no dots or crosses are drawn, but with a plus to show that it has a positive charge, a dot and cross diagram is drawn.