Question

How can I write the formula for potassium nitride?

Answer 1

Alkali metals are chemical elements that can easily lose electrons. Potassium is an element that belongs to alkali earth metal. Non-metals are chemical elements that can attract electrons. Nitrogen is an example of a non-metal. Potassium and nitrogen combine with each other and form an ionic compound known as potassium nitride.

Complete answer:
The periodic table is the basic concept in chemical sciences that represents the systematic arrangement of chemical elements arranged in the vertical columns and horizontal rows according to an increase in atomic numbers.
The vertical columns were known as groups and the horizontal rows were known as periods. There are a total of $118$ elements arranged in $7$ periods and $18$ groups.
Potassium is an element with atomic number $19$ that belongs to alkali earth metals and has one valence electron in its outer shell. Nitrogen is an element with atomic number $7$ belonging to group $15$ and has three valence electrons in its outer shell.
Potassium loses electrons and nitrogen tries to attract electrons. Both these elements combined to form an ionic compound by sharing electrons. three potassium atoms combine with one atom of nitrogen to form a compound known as potassium nitride.
The formula for potassium nitride is ${K_3}N$ .

Note:
While writing the ionic compounds that were formed by the combination of metal and non-metal, the electrons lost by all the metals must be equal to the electrons gained by all non-metals in that compound. In ${K_3}N$ , potassium atoms lose three electrons and gain stability and nitrogen attracts those three electrons to attain completely filled stability.