Question

An element has 2 electrons in its N shell. It reacts with a non-metal of atomic number 7. The compound formed reacts with warm water and produces a basic gas. Identify the elements and write a balanced chemical reaction.

Answer 1

An element that has 2 electrons in its N shell is Magnesium. The atomic number of magnesium is 12, and its electronic configuration is (2, 8, 2). A non-metal having atomic number 7 is Nitrogen. The compound formed with Magnesium and Nitrogen is Magnesium Nitride (Mg₃N₂).

\[\ce{3Mg + N2 ->[800^\circ C] Mg3N2}\]

When Magnesium Nitride reacts with warm water, it produces ammonia gas.

The balance equation is as follows:

\[\ce{Mg3N2 + \underset{(warm water)}{6H2O} -> 3Mg(OH)2 + 2NH3 \uparrow}\]