Question

Which from following elements is in liquid state at room temperature?

• A. Se
• B. Br
• C. I
• D. S

Hint:

Remember that only two elements are liquids at standard room temperature ($25^{\circ}C$): Bromine (a nonmetal) and Mercury (a metal). All other elements are either solids or gases.

Answer 1

The Correct Option is B

Step 1: Definition of room temperature Room temperature is generally taken as approximately $25^\circ\mathrm{C}$ (or $298\,\mathrm{K}$), corresponding to standard ambient conditions.
Step 2: Physical states of the given elements at room temperature

• A. Selenium (Se): Selenium is a non-metal that exists as a solid at room temperature.
• B. Bromine (Br): Bromine is a reddish-brown liquid at room temperature. It is one of the very few elements that exist in liquid state under these conditions.
• C. Iodine (I): Iodine is a solid at room temperature and sublimes to form a violet vapour.
• D. Sulfur (S): Sulfur exists as a yellow solid (rhombic form) at room temperature.

Step 3: Conclusion Among the given elements, only bromine is in the liquid state at room temperature. \[ \boxed{\text{Bromine (Br) \]