Sodium and potassium occur-

Options

A. In native state
B. In combined state
C. In gaseous state
D. All

Answer

**Step-by-Step Solution:**

1. **Identify the Elements**: The question mentions sodium (Na) and potassium (K). Both of these elements are classified as alkali metals in Group 1 of the periodic table.

2. **Understand the Electronic Configuration**: The electronic configuration of alkali metals can be represented as \( ns^1 \), where \( n \) is the principal quantum number. For sodium, the configuration is \( 1s^2 2s^2 2p^6 3s^1 \) and for potassium, it is \( 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 \). This indicates that both elements have one electron in their outermost shell.

3. **Reactivity of Alkali Metals**: Alkali metals are highly reactive due to their tendency to lose that one valence electron to achieve a stable electronic configuration (similar to that of noble gases). This reactivity means that sodium and potassium do not exist in their free (native) state in nature.

4. **Existence in Combined State**: Because of their high reactivity, sodium and potassium are typically found in nature in a combined state, forming compounds with other elements. For example, sodium forms compounds like sodium chloride (NaCl) and potassium forms potassium chloride (KCl).

5. **Conclusion**: Based on the above points, we can conclude that sodium and potassium do not occur in a native state or gaseous state; they primarily exist in a combined state due to their high reactivity.

6. **Final Answer**: The correct answer is that sodium and potassium occur in a combined state.