Highly reactive elements occurs in nature in_____state.

Answer

**Step-by-Step Solution:**

1. **Identify the Nature of Highly Reactive Elements**: Highly reactive elements can be classified into two categories: highly electropositive metals and highly electronegative non-metals.

2. **Examples of Highly Reactive Metals**: Common examples of highly reactive metals include alkali metals (like sodium and potassium) and alkaline earth metals (like magnesium). These metals are known for their high reactivity.

3. **Examples of Highly Reactive Non-Metals**: Non-metals that are highly reactive include elements like fluorine, oxygen, nitrogen, and chlorine. These elements are characterized by their high electronegativity.

4. **Occurrence in Nature**: Due to their high reactivity, both highly electropositive metals and highly electronegative non-metals do not exist in their free or elemental form in nature. Instead, they are found in a combined state.

5. **Illustration with Examples**:
- Sodium is found in nature as sodium chloride (table salt), sodium nitrate, and sodium carbonate.
- Potassium is found in the form of potassium nitrate and potassium chloride.
- Magnesium occurs in various compounds such as magnesium carbonate, magnesium bicarbonate, and magnesium chloride.
- Non-metals like fluorine and nitrogen are found in compounds such as hydrogen chloride gas and various nitrates.

6. **Conclusion**: Given that highly reactive elements are always found in combination with other elements due to their reactivity, the answer to the fill-in-the-blank question is "combined state".

**Final Answer**: Highly reactive elements occur in nature in **combined state**.

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