Alkali metals forms following compound

Options

A. All form amide `MNH_(2)`
B. All form ionic salt like hydride `MH`
C. All form superoxide like `KO_(2)`
D. All form nitrides

Explanation

To solve the question regarding which compounds are formed by alkali metals, we will analyze each statement provided in the question step by step.

### Step 1: Identify Alkali Metals
Alkali metals are located in Group 1 of the periodic table. The alkali metals include:
- Lithium (Li)
- Sodium (Na)
- Potassium (K)
- Rubidium (Rb)
- Cesium (Cs)
- Francium (Fr)

**Hint:** Remember that alkali metals are highly reactive and have one electron in their outermost shell.

### Step 2: Analyze the First Statement
The first statement claims that all alkali metals can form amides (e.g., LiNH2, NaNH2).
- **Fact Check:** Only lithium (Li), sodium (Na), and potassium (K) can form stable amides. Rubidium (Rb) and cesium (Cs) do not form amides.
- **Conclusion:** This statement is **incorrect**.

**Hint:** Recall that not all alkali metals have the same ability to form compounds, especially with nitrogen.

### Step 3: Analyze the Second Statement
The second statement claims that all alkali metals can form ionic salts (e.g., MX).
- **Fact Check:** Alkali metals readily form ionic compounds with halides, hydroxides, and hydrides. For example, LiCl, NaCl, KOH, and KH are all ionic salts.
- **Conclusion:** This statement is **correct**.

**Hint:** Ionic compounds typically consist of a metal and a non-metal, where the metal donates an electron.

### Step 4: Analyze the Third Statement
The third statement claims that all alkali metals can form superoxides (e.g., KO2).
- **Fact Check:** Lithium (Li) forms only oxides (Li2O), sodium (Na) forms peroxides (Na2O2), while potassium (K), rubidium (Rb), and cesium (Cs) can form superoxides (KO2, RbO2, CsO2).
- **Conclusion:** This statement is **incorrect**.

**Hint:** Superoxides are a specific type of oxide that contain the superoxide ion (O2^-).

### Step 5: Analyze the Fourth Statement
The fourth statement claims that all alkali metals can form nitrides.
- **Fact Check:** Only lithium (Li) forms a stable nitride (Li3N). Sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs) do not form stable nitrides.
- **Conclusion:** This statement is **incorrect**.

**Hint:** Nitrides are compounds that contain nitrogen in a -3 oxidation state, and not all alkali metals can achieve this.

### Final Conclusion
After analyzing all statements, the only correct statement is that alkali metals can form ionic salts. Therefore, the answer to the question is:

**Answer:** The correct statement is option B: All alkali metals can form ionic salts.