Question

Compare atoms and ions of any three elements. Show the number of electrons before and after ion formation using bar graphs.

Answer 1

The number of electrons in an atom changes when it gains or loses electrons to form an ion.

Element	Electrons in Atom	Ion Formed	Electrons in Ion
Sodium (Na)	11	Na⁺	10
Magnesium (Mg)	12	Mg²⁺	10
Chlorine (Cl)	17	Cl⁻	18

Bar Graph: Comparison of Electrons in Atoms and Ions

Conclusion:

1. Sodium loses 1 electron to form Na⁺.

2. Magnesium loses 2 electrons to form Mg²⁺.

3. Chlorine gains 1 electron to form Cl⁻.

Thus, positive ions are formed by losing electrons, while negative ions are formed by gaining electrons.