Question

Which of the following elements will gain electrons to form an ion?

Option 1: P
Option 2: Fe
Option 3: Pb
Option 4: Se

Answer 1

Selenium (Se) will gain electrons to form an ion among the options P, Fe, Pb, and Se, as it is a nonmetal and tends to gain 2 electrons to achieve a stable negative ion (Se2-). So, the correct option is 4.

Step-by-step explanation:

The element that will gain electrons to form an ion among the options provided is Se (selenium). In general, nonmetals gain electrons to achieve a full valence shell and form anions. Considering the group trends in the periodic table, Phosphorus (P) being in group 15 tends to gain 3 electrons to form P3-. However, Transition metals like Iron (Fe) and Lead (Pb) typically lose electrons to form cations (positive ions), and so does not generally gain electrons to form anions. Thus, out of the options provided, Selenium (Se), being a nonmetal in group 16, is expected to gain 2 electrons to form the Se2- ion and form a stable negative ion in binary ionic compounds.