`Li` does resemble other alkali metals in following properties:

Options

A. `Li_(2)CO_(3)` decomposes into oxides while other alkali carbonates are thermally stable
B. `LiCI` is predominatly covalent
C. `Li_(3)N` is stable
D. All

Answer

To solve the question regarding the properties of lithium (`Li`) that resemble other alkali metals, we will analyze each of the given options step by step.

### Step 1: Analyze the first option
**Statement**: `Li2CO3` decomposes into oxides while other alkali carbonates are thermally stable.

- **Explanation**: Lithium carbonate (`Li2CO3`) is unique among the alkali metal carbonates as it decomposes upon heating to form lithium oxide (`Li2O`) and carbon dioxide (`CO2`). This is in contrast to other alkali metal carbonates, which are generally stable and do not decompose easily under similar conditions.
- **Reaction**:
\[ \text{Li}_2\text{CO}_3 \xrightarrow{\text{heat}} \text{Li}_2\text{O} + \text{CO}_2 \]
- **Conclusion**: This option is correct.

### Step 2: Analyze the second option
**Statement**: `LiCl` is predominantly covalent.

- **Explanation**: Lithium chloride (`LiCl`) exhibits covalent character due to the small size and high charge density of the lithium ion, which leads to significant polarization of the chloride ion. As a result, `LiCl` does not dissociate into ions in the molten state, making it non-conductive. It can also dissolve in non-polar solvents like ether, which is characteristic of covalent compounds.
- **Conclusion**: This option is correct.

### Step 3: Analyze the third option
**Statement**: `Li3N` is stable.

- **Explanation**: Lithium nitride (`Li3N`) is indeed stable, and it is unique among the alkali metals as it is the only nitride formed by a group 1 element. Other alkali metals do not form stable nitrides. This stability is attributed to the strong ionic bonding in `Li3N`.
- **Conclusion**: This option is correct.

### Step 4: Analyze the fourth option
**Statement**: All of these.

- **Explanation**: Since we have established that all the previous statements about lithium are correct, this option is also correct.
- **Conclusion**: The correct answer is option 4, which states that all the properties mentioned are true for lithium.

### Final Answer
The correct answer is **Option 4: All of these**.

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