Answer:
Explanation:
Alkaline earth metals are the family of metals that belong to group (column) number 2 in the periodic table.
You can tell the number of valence electrons of the representative elements by the number of column: the ones digit is the number of valence electrons.
This is how this works:
Column number ones digit number of valence electrons
1 1 1 (alkali metals)
2 2 2 (alkaline earth metals)
13 3 3
14 4 4
15 5 5
16 6 6
17 7 7 (halogens)
18 8 8 (noble gases).
Of course, this is consequence of the electron configurations.