Refer attached figure.
Step-by-step explanation:
The electron dot structure (Lewis structure) represents the number of valence electrons of an element in terms of dots around the symbol of the element.
Number of dots = Number of valence electrons
1. Aluminum:
Symbol = Al
Atomic number = 13
Main Group number = IIIA (3A) of the periodic table.
Group = Group 13 of periodic table
Number of valence electrons = Main group number = 3
Electron dot structure = (See attached figure)
2. Chlorine
Symbol = Cl
Atomic number = 17
Main group number = VIA (7A) of the periodic table.
Group = Group 17 of periodic table
Number of valence electrons = Main group number = 7
Electron dot structure = (See attached figure)