What are the chemical names of these compounds?
KF:
Mg3N2:

Magnesium nitride

Explanation:

The name of compound 'KF' is, Potassium fluoride.

The name of compound 'Mg₃N₂' is, Magnesium nitride.

Explanation:

Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.

Ionic compound are usually formed when a metal reacts with a non-metal.

The nomenclature of ionic compounds is given by:

1. Positive ion is written first.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

3. In case of transition metals, the oxidation state are written in roman numerals in bracket in-front of positive ions.

(a) KF

KF is an ionic compound because potassium element is a metal and fluorine element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.

Thus, the name of compound 'KF' is, Potassium fluoride.

(b) Mg₃N₂

Mg₃N₂ is an ionic compound because magnesium element is a metal and nitrogen element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.

Thus, the name of compound 'Mg₃N₂' is, Magnesium nitride.

first one is the correct answer

it is the most commonly accepted one