The correct order of reactivity in alkali metals is:

Options

A. `Li gt Na gt K`
B. `Na gt Li gt K`
C. `K gt Li gt Na`
D. `K gt Na gt Li`

Answer

To determine the correct order of reactivity in alkali metals, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Alkali Metals**:
- Alkali metals are found in Group 1 of the periodic table. The common alkali metals include Lithium (Li), Sodium (Na), and Potassium (K).

2. **Understand Electron Configuration**:
- Alkali metals have one electron in their outermost shell, which gives them the general electronic configuration of ns¹. This means they have a strong tendency to lose this single electron to achieve a stable electronic configuration similar to that of the nearest noble gas.

3. **Reactivity Trend**:
- The reactivity of alkali metals increases as you move down the group in the periodic table. This is because as you go down the group, the atomic size increases, and the outermost electron is further from the nucleus. This makes it easier for the atom to lose the outer electron.

4. **Compare Reactivity of Lithium, Sodium, and Potassium**:
- Among Lithium, Sodium, and Potassium:
- Lithium (Li) has the smallest atomic size and is the least reactive.
- Sodium (Na) is more reactive than Lithium.
- Potassium (K) has the largest atomic size among the three and is the most reactive.

5. **Conclusion**:
- Therefore, the correct order of reactivity in alkali metals from highest to lowest is:
- Potassium (K) > Sodium (Na) > Lithium (Li).

### Final Answer:
The correct order of reactivity in alkali metals is: **Potassium > Sodium > Lithium**.

---