Question

When a chlorine atom becomes chloride ion,its size?
A. Remains unaltered
B. Increases
C. Decreases
D. None of these

Answer 1

Hint: Chlorine is a highly negative ion, if the number of atoms it leads in the increase of radius and ultimately the repulsion increases too.Cl atomic number is 17 (17 electrons, 17 protons), when it gains electrons then Cl atom becomes Cl- which consists of 18 electrons and 17 protons. Due to the excess of electron, electron – electron repulsion becomes predominant compared to electron – proton attraction. Due to this repulsion Cl- size becomes larger.

Complete answer:
Electron pair repulsion is a theory that informs a wide variety of scientific disciplines. Physics, engineering and chemistry often use this principle. The electron pairs around a central atom orient themselves as far away as possible. Electron pair repulsion is used to predict the geometry of a molecule or aqueous atomic ion. The shape of a molecule or ion is controlled by the arrangement of electron pairs around the central atom. All we need to do is find out how many electrons are coupled at the bonding level, and then arrange to produce a minimum amount of repulsion between them.
In a covalent bond, a pair of electrons is shared between two atoms. In a polyatomic molecule, several atoms are linked to a central atom using two or more electron pairs. Repulsion between negatively charged electron pairs or between lone pairs causes them to expand more and more.

Hence, the answer to the above question is option B.

Note: Importance of chlorine,Chlorine is a disinfectant as it kills bacteria. It also helps in residual protection against recontamination. Chlorine plays an important role in harnessing solar energy too.