How do non-metals occur in nature ? How are they extracted//isolated from their natural sources ?

Explanation

### Step-by-Step Text Solution

**Step 1: Understanding the Occurrence of Non-Metals in Nature**
Non-metals occur in nature in two primary states: free state and combined state.

- **Free State:** Some non-metals exist in their elemental form, which means they are not combined with other elements. For example, noble gases like helium, neon, argon, krypton, xenon, and radon are found in the free state.

- **Combined State:** Other non-metals are found in combination with other elements. For instance, hydrogen, halogens (like fluorine and chlorine), oxygen, nitrogen, and carbon can be found both in free state and combined state.
...