Select correct statement:

Options

A. Oxides `(M_(2)O)` and peroxides `(M_(2)O_(2))` of alkali metals are diamagnetic and colourless.
B. Superoxides `(MO_(2))` of alkali metals are paramagnetic.
C. Li and Na do not form superoxides.
D. All are correct.

Answer

To solve the question of selecting the correct statement regarding alkali metals, let's analyze each of the provided statements step by step.

### Step 1: Analyze the first statement
**Statement:** "Oxides and peroxides of alkali metals are diamagnetic and colorless."

- **Oxides of Alkali Metals:** The oxide of alkali metals can be represented as \( M_2O \) where \( M \) is the alkali metal. The ions present are \( M^+ \) and \( O^{2-} \).
- The \( M^+ \) ion has a noble gas electron configuration, meaning all its electrons are paired, making it diamagnetic.
- The \( O^{2-} \) ion has the electronic configuration of neon, which also means all its electrons are paired, hence it is also diamagnetic.
- Since both ions are diamagnetic, the oxide \( M_2O \) is diamagnetic.

- **Peroxides of Alkali Metals:** The peroxide can be represented as \( M_2O_2 \) where the ions are \( M^+ \) and \( O_2^{2-} \).
- The \( O_2^{2-} \) ion (peroxide ion) has an electronic configuration where all electrons are paired, making it diamagnetic.
- Therefore, the peroxide \( M_2O_2 \) is also diamagnetic.

- **Conclusion:** Both oxides and peroxides of alkali metals are indeed diamagnetic and colorless. Thus, this statement is correct.

### Step 2: Analyze the second statement
**Statement:** "Super oxides of alkali metals are paramagnetic."

- **Superoxides of Alkali Metals:** Superoxides can be represented as \( MO_2 \) where the ions are \( M^+ \) and \( O_2^{-} \).
- The \( M^+ \) ion is still diamagnetic.
- The \( O_2^{-} \) ion (superoxide ion) has an unpaired electron in its electronic configuration, which makes it paramagnetic.

- **Conclusion:** Since the superoxide ion has unpaired electrons, superoxides of alkali metals are indeed paramagnetic. Thus, this statement is correct.

### Step 3: Analyze the third statement
**Statement:** "Lithium and sodium do not form super oxides."

- **Lithium:** Lithium primarily forms the oxide \( Li_2O \) and does not form superoxides.
- **Sodium:** Sodium forms \( Na_2O \) (monoxide) when limited air is supplied and \( Na_2O_2 \) (peroxide) when burned in excess air. Sodium does not form superoxides.
- **Other Alkali Metals:** Potassium, rubidium, and cesium do form superoxides.

- **Conclusion:** The statement is correct; lithium and sodium do not form superoxides.

### Final Conclusion
All three statements are correct. Therefore, the correct answer is:
**D) All of the above are correct.**

---