Core Periodicity I: Chemical Properties

Core Periodicity: Chemical Properties

Slide 5 of 31

Similarities in Group I Metals

Alkali metals are all soft and have low melting point.

Chemistry dominated by the loss of their single s electron:

M ® M+ + e-

Reactivity increases as we move down the group because ionization energy decreases.

1. Alkali metals react with water to form MOH and hydrogen
gas:

2M(s) + 2H2O(l) ® 2MOH(aq) + H2(g)

–The reaction is more and more vigorous down the group.

–While lithium reacts quietly with water, sodium darts about making a fizzing sound and at the end may produce a pop sound when the hydrogen catches on fire.

–Potassium when introduced into the water produces a burning flame (picture above).