Question

name: zach
lewis (electron dot) diagrams worksheet - review

1. draw lewis dot diagrams for the following atoms

li f si n mg cs as b
br ba k o p xe al s

1. i) draw electron dot diagrams for the following substances:

ii) identify the type of bonding present in each substance.
if ionic you dont need to draw dot diagram
h₂ nacl hbr mgf₂ co₂
pcl₃ bao h₂o al₂o₃ nh₃
o₂ ch₄ k₂o n₂ hcl

Explanation:

Step1: Find valence electrons for atoms

Valence electrons = main group number (from periodic table)

• Li: 1, F:7, Si:4, N:5, Mg:2, Cs:1, As:5, B:3
• Br:7, Ba:2, K:1, O:6, P:5, Xe:8, Al:3, S:6

Step2: Draw single-atom Lewis diagrams

Place valence electrons as dots around element symbol, max 2 per side, 8 total.

• $\text{Li} \cdot$
• $\cdot \ddot{\text{F}} :$
• $\cdot \ddot{\text{Si}} \cdot$

$\quad \cdot$

• $\cdot \ddot{\text{N}} :$

$\quad \cdot$

• $\text{Mg} :$
• $\text{Cs} \cdot$
• $\cdot \ddot{\text{As}} :$

$\quad \cdot$

• $\cdot \text{B} \cdot$

$\quad \cdot$

• $: \ddot{\text{Br}} :$

$\quad \cdot$

• $\text{Ba} :$
• $\text{K} \cdot$
• $: \ddot{\text{O}} :$
• $\cdot \ddot{\text{P}} :$

$\quad \cdot$

• $: \ddot{\text{Xe}} :$

$\quad \cdot \quad \cdot$

• $\cdot \text{Al} \cdot$

$\quad \cdot$

• $: \ddot{\text{S}} :$

Step3: Classify bonding for compounds

Ionic = metal + nonmetal; Covalent = nonmetal + nonmetal

• $\text{H}_2$: Covalent; $\text{NaCl}$: Ionic; $\text{HBr}$: Covalent; $\text{MgF}_2$: Ionic; $\text{CO}_2$: Covalent
• $\text{PCl}_3$: Covalent; $\text{BaO}$: Ionic; $\text{H}_2\text{O}$: Covalent; $\text{Al}_2\text{O}_3$: Ionic; $\text{NH}_3$: Covalent
• $\text{O}_2$: Covalent; $\text{CH}_4$: Covalent; $\text{K}_2\text{O}$: Ionic; $\text{N}_2$: Covalent; $\text{HCl}$: Covalent

Step4: Draw covalent compound Lewis diagrams

Share electrons to fill octets (duet for H):

• $\text{H}_2$: $\text{H} - \text{H}$ (or $\text{H} \cdot \text{H}$)
• $\text{HBr}$: $\text{H} - \ddot{\text{Br}} :$

$\quad :$

• $\text{CO}_2$: $: \ddot{\text{O}} = \text{C} = \ddot{\text{O}} :$
• $\text{PCl}_3$: $: \ddot{\text{Cl}} - \ddot{\text{P}} - \ddot{\text{Cl}} :$

$\quad : \quad \cdot \quad :$
$\quad \text{Cl} :$

• $\text{H}_2\text{O}$: $\text{H} - \ddot{\text{O}} - \text{H}$

$\quad :$

• $\text{NH}_3$: $\text{H} - \ddot{\text{N}} - \text{H}$

$\quad : \quad \text{H}$

• $\text{O}_2$: $: \ddot{\text{O}} = \ddot{\text{O}} :$
• $\text{CH}_4$: $\text{H}$

$\quad |$
$\text{H} - \text{C} - \text{H}$
$\quad |$
$\text{H}$

• $\text{N}_2$: $: \text{N} \equiv \text{N} :$
• $\text{HCl}$: $\text{H} - \ddot{\text{Cl}} :$

$\quad :$
Ionic compounds ($\text{NaCl}$, $\text{MgF}_2$, $\text{BaO}$, $\text{Al}_2\text{O}_3$, $\text{K}_2\text{O}$) do not use shared electron dot diagrams; they are represented as ions (e.g., $\text{Na}^+ : \ddot{\text{Cl}} :^-$)

Answer:

1. Single-Atom Lewis Diagrams:

• $\text{Li} \cdot$
• $\cdot \ddot{\text{F}} :$
• $\cdot \ddot{\text{Si}} \cdot$

$\quad \cdot$

• $\cdot \ddot{\text{N}} :$

$\quad \cdot$

• $\text{Mg} :$
• $\text{Cs} \cdot$
• $\cdot \ddot{\text{As}} :$

$\quad \cdot$

• $\cdot \text{B} \cdot$

$\quad \cdot$

• $: \ddot{\text{Br}} :$

$\quad \cdot$

• $\text{Ba} :$
• $\text{K} \cdot$
• $: \ddot{\text{O}} :$
• $\cdot \ddot{\text{P}} :$

$\quad \cdot$

• $: \ddot{\text{Xe}} :$

$\quad \cdot \quad \cdot$

• $\cdot \text{Al} \cdot$

$\quad \cdot$

• $: \ddot{\text{S}} :$

2. Compound Diagrams & Bonding:

Substance	Lewis Diagram (Covalent Only)	Bonding Type
$\text{NaCl}$	(Ionic: $\text{Na}^+ : \ddot{\text{Cl}} :^-$)	Ionic
$\text{HBr}$	$\text{H} - \ddot{\text{Br}} :$ <br> $\quad :$	Covalent
$\text{MgF}_2$	(Ionic: $\text{Mg}^{2+} [: \ddot{\text{F}} :]^-_2$)	Ionic
$\text{CO}_2$	$: \ddot{\text{O}} = \text{C} = \ddot{\text{O}} :$	Covalent
$\text{PCl}_3$	$: \ddot{\text{Cl}} - \ddot{\text{P}} - \ddot{\text{Cl}} :$ <br> $\quad : \quad \cdot \quad :$ <br> $\quad \text{Cl} :$	Covalent
$\text{BaO}$	(Ionic: $\text{Ba}^{2+} [: \ddot{\text{O}} :]^{2-}$)	Ionic
$\text{H}_2\text{O}$	$\text{H} - \ddot{\text{O}} - \text{H}$ <br> $\quad :$	Covalent
$\text{Al}_2\text{O}_3$	(Ionic: $\text{Al}^{3+}_2 [: \ddot{\text{O}} :]^{2-}_3$)	Ionic
$\text{NH}_3$	$\text{H} - \ddot{\text{N}} - \text{H}$ <br> $\quad : \quad \text{H}$	Covalent
$\text{O}_2$	$: \ddot{\text{O}} = \ddot{\text{O}} :$	Covalent
$\text{CH}_4$	$\text{H}$ <br> $\quad	$ $\text{H} - \text{C} - \text{H}$ $\quad	$ $\text{H}$	Covalent
$\text{K}_2\text{O}$	(Ionic: $\text{K}^+_2 [: \ddot{\text{O}} :]^{2-}$)	Ionic
$\text{N}_2$	$: \text{N} \equiv \text{N} :$	Covalent
$\text{HCl}$	$\text{H} - \ddot{\text{Cl}} :$ <br> $\quad :$	Covalent