Show the electron dot representation of (A) LiCl (B) CaO

To show the electron dot representation (also known as Lewis dot structure) for ionic compounds like LiCl and CaO, we focus on the valence electrons of each atom involved in the bonding. Here’s a breakdown of each compound:

### (A) Lithium Chloride (LiCl)

**Step 1: Identify the valence electrons.**
- Lithium (Li) has 1 valence electron (Group 1).
- Chlorine (Cl) has 7 valence electrons (Group 17).

**Step 2: Represent the valence electrons using dots.**
- Lithium: \( \text{Li} \cdot \)
- Chlorine: \( \text{Cl} : : : : : : \) (7 dots surrounding Cl)

**Step 3: Show the transfer of electrons.**
- Lithium will lose its one valence electron to achieve a stable electronic configuration (like helium), becoming \( \text{Li}^+ \).
- Chlorine will gain that electron, achieving a stable octet configuration, becoming \( \text{Cl}^- \).

**Final Representation:**
The electron dot representation can be illustrated as follows:

\[ \text{Li} \rightarrow \text{Cl} : : : : : : \]
\[ \text{Li}^+ \; [ \text{Cl}^- ] \]

Where the arrow indicates the transfer of the electron from Li to Cl.

### (B) Calcium Oxide (CaO)

**Step 1: Identify the valence electrons.**
- Calcium (Ca) has 2 valence electrons (Group 2).
- Oxygen (O) has 6 valence electrons (Group 16).

**Step 2: Represent the valence electrons using dots.**
- Calcium: \( \text{Ca} \cdot \cdot \)
- Oxygen: \( \text{O} : : : : : : \) (6 dots surrounding O)

**Step 3: Show the transfer of electrons.**
- Calcium will lose its two valence electrons to achieve a stable configuration (like neon), becoming \( \text{Ca}^{2+} \).
- Oxygen will gain those two electrons to achieve a stable octet configuration, becoming \( \text{O}^{2-} \).

**Final Representation:**
The electron dot representation can be illustrated as follows:

\[ \text{Ca} \rightarrow \text{O} : : : : : : \]
\[ \text{Ca}^{2+} \; [ \text{O}^{2-} ] \]

Again, the arrow indicates the transfer of electrons from Ca to O.

### Summary

- **LiCl**: \( \text{Li} \rightarrow \text{Cl} : : : : : : \)
- **CaO**: \( \text{Ca} \rightarrow \text{O} : : : : : : \)

In these representations, we see how electrons are transferred from the metal to the nonmetal, forming the ionic bonds in both compounds.