Aneutral atom possesses an atomic number of 15 and an atomic mass of 31. three electrons are gained. what is the result of this conversion?

Neutral atom carries atomic number 15 and atomic mass  31. This is phosphorous (P) atom with 15 electron. We know no. of proton are equal to no. of electron in neutral atom. After gain of 3 electrons, total number of electrons in P atom will change to 18. This results neutral atom onversion into a negative charge ion with a charge of 3-.

No is the answer to the question