Question

write the number of protons and draw dots for each electron in each of the atoms below. look for trends/patterns to discuss.
column 1 (valence # 1, oxidation #), column 2 (valence # 2, oxidation #), column 3 (valence # 3, oxidation #), column 4 (valence # 4, oxidation #), column 5 (valence # 5, oxidation #), column 6 (valence # 6, oxidation #), column 7 (valence # 7, oxidation #), column 8 (valence # 8, oxidation #)
row 1: h, he
row 2: li, be, b, c, n, o, f, ne
row 3: na, mg, al, si, p, s, cl, ar
valence # -, oxidation # -

Answer:

To solve for the number of protons and valence electrons (and draw electron dots) for each atom, we use the following principles:

Step 1: Number of Protons

The number of protons in an atom is equal to its atomic number. For example:

• Hydrogen (H): Atomic number = 1 → 1 proton.
• Helium (He): Atomic number = 2 → 2 protons.
• Lithium (Li): Atomic number = 3 → 3 protons.
• Beryllium (Be): Atomic number = 4 → 4 protons.
• Boron (B): Atomic number = 5 → 5 protons.
• Carbon (C): Atomic number = 6 → 6 protons.
• Nitrogen (N): Atomic number = 7 → 7 protons.
• Oxygen (O): Atomic number = 8 → 8 protons.
• Fluorine (F): Atomic number = 9 → 9 protons.
• Neon (Ne): Atomic number = 10 → 10 protons.
• Sodium (Na): Atomic number = 11 → 11 protons.
• Magnesium (Mg): Atomic number = 12 → 12 protons.
• Aluminum (Al): Atomic number = 13 → 13 protons.
• Silicon (Si): Atomic number = 14 → 14 protons.
• Phosphorus (P): Atomic number = 15 → 15 protons.
• Sulfur (S): Atomic number = 16 → 16 protons.
• Chlorine (Cl): Atomic number = 17 → 17 protons.
• Argon (Ar): Atomic number = 18 → 18 protons.

Step 2: Valence Electrons (and Dot Diagrams)

Valence electrons are the outermost electrons. For main - group elements (Groups 1 - 2, 13 - 18), the number of valence electrons is related to the group number:

• Group 1 (Column 1): 1 valence electron (e.g., H, Li, Na).
• Group 2 (Column 2): 2 valence electrons (e.g., Be, Mg).
• Group 13 (Column 3): 3 valence electrons (e.g., B, Al).
• Group 14 (Column 4): 4 valence electrons (e.g., C, Si).
• Group 15 (Column 5): 5 valence electrons (e.g., N, P).
• Group 16 (Column 6): 6 valence electrons (e.g., O, S).
• Group 17 (Column 7): 7 valence electrons (e.g., F, Cl).
• Group 18 (Column 8): 8 valence electrons (noble gases, e.g., He, Ne, Ar; He has 2, which is a full outer shell).

Step 3: Oxidation Number (General Trend)

• Group 1: +1 (lose 1 valence electron).
• Group 2: +2 (lose 2 valence electrons).
• Group 13: +3 (lose 3 valence electrons).
• Group 14: +4 or -4 (gain or lose 4 electrons).
• Group 15: -3 (gain 3 electrons) or +5 (lose 5 electrons).
• Group 16: -2 (gain 2 electrons) or +6 (lose 6 electrons).
• Group 17: -1 (gain 1 electron) or +7 (lose 7 electrons).
• Group 18: 0 (stable, no gain/loss).

Example: Hydrogen (H)

• Protons: 1 (atomic number 1).
• Valence electrons: 1 (Group 1).
• Oxidation number: +1 (or -1 in some cases, but +1 is common).
• Electron dot: $\boldsymbol{\cdot \text{H}}$

Example: Helium (He)

• Protons: 2 (atomic number 2).
• Valence electrons: 2 (full outer shell, Group 18).
• Oxidation number: 0.
• Electron dot: $\boldsymbol{:\text{He}}$

Example: Lithium (Li)

• Protons: 3 (atomic number 3).
• Valence electrons: 1 (Group 1).
• Oxidation number: +1.
• Electron dot: $\boldsymbol{\cdot \text{Li}}$

Example: Oxygen (O)

• Protons: 8 (atomic number 8).
• Valence electrons: 6 (Group 16).
• Oxidation number: -2 (common, gains 2 electrons).
• Electron dot: $\boldsymbol{:\overset{..}{O}:}$

Filling the Table (Summary for Key Atoms)

Atom	Protons	Valence Electrons	Oxidation Number	Electron Dot
He	2	2	0	$:$He
Li	3	1	+1	$\cdot$Li
Be	4	2	+2	$:\text{Be}$
B	5	3	+3	$\cdot \overset{..}{\text{B}}$
C	6	4	+4 / -4	$\cdot \overset{..}{\text{C}} \cdot$
N	7	5	-3 / +5	$:\overset{..}{\text{N}} \cdot$
O	8	6	-2 / +6	$:\overset{..}{O}:$
F	9	7	-1 / +7	$:\overset{...}{F} \cdot$
Ne	10	8	0	$:\overset{..}{Ne}:$
Na	11	1	+1	$\cdot$Na
Mg	12	2	+2	$:\text{Mg}$
Al	13	3	+3	$\cdot \overset{..}{\text{Al}}$
Si	14	4	+4 / -4	$\cdot \overset{..}{\text{Si}} \cdot$
P	15	5	-3 / +5	$:\overset{..}{\text{P}} \cdot$
S	16	6	-2 / +6	$:\overset{..}{S}:$
Cl	17	7	-1 / +7	$:\overset{...}{Cl} \cdot$
Ar	18	8	0	$:\overset{..}{Ar}:$

Trends/Patterns

• Protons: Increase by 1 from left to right across a row (period) and down a column (group).
• Valence Electrons: Increase by 1 from left to right across a period (Group 1 → Group 18, excluding He, which has 2).
• Oxidation Number: For main - group elements, follows the group number (positive for metals, negative for non - metals, 0 for noble gases).

To complete the table, fill in the protons (atomic number), valence electrons (group - based), oxidation number (trend - based), and draw dots for valence electrons as shown above.