Describe the use of a flame test to identify the cations: (a) lithium, ( Li^+ ) (b) sodium, ( Na^+ ) (c) potassium, ( K^+ ) (d) calcium, ( Ca^{2+} ) (e) barium, ( Ba^{2+} ) (f) copper(II), ( Cu^{2+} )

Describe the relationship between group number and the charge of the ions formed from elements in that group

Describe the Group I alkali metals, lithium, sodium and potassium, as relatively soft metals with general trends down the group, limited to: (a) decreasing melting point (b) increasing density (c) increasing reactivity