Group 1 and 2 Compounds

Group 1 (Alkali Metals) and Group 2 (Alkaline Earth Metals) Compounds:

Group 1 metals react readily with non-metals to form ionic compounds.
Alkali metals react with oxygen to form oxides, with hydrogen to form hydrides, and with halogens to form halides.
Lithium, from Group 1, forms Li2O, a simple oxide, while sodium forms Na2O2, a peroxide, and the other Group 1 metals form superoxides (KO2, RbO2, CsO2).
The solubility and reactivity of Group 2 metal compounds increase down the group due to the decrease in ionisation energy.
Group 2 metals react with water to a different extent: Mg does not react with cold water but with boiling water or steam, while Ba reacts readily with cold water.
Alkaline Earth Metal oxides and hydroxides are bases, and their reactivity increases down the group. They react with water to form alkaline solutions.
The trend in melting points and boiling points in Group 1 and Group 2 elements is due to the strength of metallic bonding, which itself depends on the charge on the ion and the size of the ion.
Trend in first ionisation energy down groups 1 and 2: decreases because the atomic radius increases, the nuclear charge increases and the electron shielding increases.
Hydrogen is not a member of Group 1 although it is located above lithium in the Periodic table. It only has one electron in its outermost shell and its chemistry is markedly different from alkali metals.
Group 1 and 2 metals and their compounds are often used in the industry. For instance, Group 1 compounds are used in various applications from table salt (NaCl) to lithium batteries. Group 2 metal compounds have applications ranging from cement (calcium oxide) to stomach antacids (magnesium hydroxide).