Question

If an electron is transferred from A and B forming A+ and B- . then above reaction is possible when

Answer 1

Answer: A is highly electropositive and B is highly electronegative

Explanation:

An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.

For example: formation of $NaCl$ is shown below:

Electronic configuration of sodium:

$[Na]=1s^22s^22p^63s^1$

Sodium atom will loose one electron to gain noble gas configuration and form sodium cation with +1 charge.

$[Na^+]=1s^22s^22p^63s^0$

Electronic configuration of chlorine:

$[Cl]=1s^22s^22p^63s^23p^5$

Chlorine atom will gain one electron to gain noble gas configuration and form chloride ion with -1 charge.

$[Cl^-]=1s^22s^22p^63s^23p^6$

Thus above reaction is possible when A is highly electropositive and B is highly electronegative