Question

What is the number of allotropes of selenium?

• A. 2
• B. 4
• C. 5
• D. 6

Hint:

Just like phosphorus has its famous red/white divisions, remember selenium by its two primary forms: red (non-metallic ring structures) and grey (the stable metallic chain conductor form)!

Answer 1

The Correct Option is A

Step 1: Place selenium.
Selenium is a Group 16 element and shows allotropy like its neighbours.

Step 2: List the main forms.
In standard texts it has two main forms: red selenium with $Se_8$ rings, and grey metallic selenium with long chains.

Step 3: Count them.
That gives two main allotropes.
\[ \boxed{2,\ \text{option 1}} \]