How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H2 + O2→ 2H2O,∆H = -571.7KJ (H = 1)

The phenomenon observed when dust particles collide randomly in a beam of sunlight is known as

In linear molecules, the bond angle is

If the atomic number of an element X is 11 and that of nitrogen is 7, the most likely formula of the nitride of X is

The mass number of an element is the sum of its

A sodium atom and a sodium ion have the same

How many unpaired electrons are there in an atom of an element with the following electronic configuration? 1s22s22p6

Radon is used as a tracer in medical research because it

What is the most probable group of an element which is a soft, silvery white solid and reacts violently with water?