Valence Electron Determination Practice Chemistry Homework Worksheet - Free Printable

Final Answer:
1. Cl: 7, O: 6, F: 7, P: 5, Al: 3
2. Be: 2, B: 3, Na: 1, H: 1, Mg: 2
3. K: 1, He: 2 (full shell), Ar: 8 (full shell), C: 4, S: 6
4. Si: 4, Li: 1, N: 5, Ne: 8 (full shell), Co: 9 (but for main-group behavior, often considered 2 or 3; however, in basic valence electron counting for transition metals, it's variable — but since this is likely a high-school worksheet, Co is commonly listed as having 2 valence electrons from the 4s orbital)

However, for standard high school chemistry (focusing on main-group elements and simple transition metal rule), the expected answers are:
Cl = 7, O = 6, F = 7, P = 5, Al = 3
Be = 2, B = 3, Na = 1, H = 1, Mg = 2
K = 1, He = 2, Ar = 8, C = 4, S = 6
Si = 4, Li = 1, N = 5, Ne = 8, Co = 2

So the final filled answers are:
Row 1: 7, 6, 7, 5, 3
Row 2: 2, 3, 1, 1, 2
Row 3: 1, 2, 8, 4, 6
Row 4: 4, 1, 5, 8, 2