Answer:
3 atoms
Explanation:
The number of atoms of the metal that would be required as it forms an anionic charge of -3 is 3 atoms.
Elements in group 1 generally have a charge of +1. They have a valency of 1
By the virtue of this;
It will take 3 atoms of a group one element to combine with an anion with a -3 charge on it.
This way, the ionic bond forms and the compound becomes neutral.
