Alkali metals are located in group 1 of the periodic table. Have a single valence electron which is easily lost from the outer shell. Alkali metals react readily with water to form hydroxides and alkaline pH solutions.
Group 1 is the first group in the periodic table containing elements that are commonly known as the Alkali metals. They are all metals and increase in reactivity down the group and when reacted with water form alkali solutions
The Group 2 Alkaline earth metals are the 2nd group in the periodic table and are just before the transition metals. They are all similar in their color of silvery/white metals and react with water to form alkaline solutions. They are however not as reactive as the group 1 metals as they have 2 valence electrons instead of 1.
The lanthanides are a series of chemicals in the expanded periodic table that have an expanded number of orbitals beyond that of the transition metals. The lanthanides are mostly soft metals with their hardness increasing across the period. Whilst they are metals and can conduct electricity the lanthanides have a relatively high resistivity.