Answer:
Table D
Step-by-step explanation:
First, remember the definitions of groups, periods, and valence electrons.
Groups are columns. On the periodic table they go from 1 to 18
Periods are rows. On the periodic table they range from 1 to 7
Valence electrons are electrons in the outermost shell of the atom in question. To determine the number of valence electrons, count which column (group) an atom is in from left to right. When counting which column an atom is in, do not count the transition metals (group 3-12) because these elements have variable valence electrons which do not follow this rule.
For example, since Ca is in group 2 (the second column from the left) this atom has two valence electrons.
Similarly, P has a valence electron number of 5 because we count from left to right: 1, 2, SKIP THE TRANSITION METALS (MIDDLE BLOCK), 3, 4, 5