Question

When one atom losses an electron and another atom simultaneously gains one, what has taken place is called _____.

Answer 1

Ionic bond

Step-by-step explanation:

Ionic bonding:-

This type of bonding is formed when there is a complete transfer of electrons from one element to another element. In this bonding one element is always a metal and another is a non-metal.

Thus, the atom which loses the electron which is gained by the another, there is a electrostatic attraction between two which which results in the formation of ionic bond.

For example:-

Calcium is the element of second group and forth period. The electronic configuration of Calcium is - 2, 8, 8, 2 or
`1s^22s^22p^63s^23p^64s^2`

There are 2 valence electrons of Calcium.

Sulfur is the element of sixteenth group and third period. The electronic configuration of sulfur is - 2, 8, 6 or
`1s^22s^22p^63s^23p^4`

There are 6 valence electrons of sulfur.

Thus, calcium loses two electrons to sulfur and sulfur accepts these electrons to form ionic bond.

Calcium sulfide,
`CaS` is formed when 2 valence electrons of calcium are loosed and they are gained by sulfur atom.