Question

1. How many of the known elements exist as gases at 25° C?
(1) 9
(2) 11
(3) 12
(4) 15​

Answer 1

Answer:

11….................

Answer 2

The correct answer is option (2) 11.

Explanation:

• 11 of the known elements exist as gases at 25° C.
• The correct answer is 11.
• The gaseous element group; hydrogen (H), nitogen (N), oxygen (O), fluorine (F), chlorine (Cl) and noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) are gases at standard temperature and pressure (STP).
• Of the known elements in the periodic table, only 11 are gases under normal atmospheric conditions.