Question

Which statement is true about the definition of electronegativity?
A) It is a property in which an atom can attract shared pairs of electrons
B) $F$ is more electronegative atom than $Cl$
C) On moving down the group electronegativity decreases
D) all of the above

Answer 1

The electronegativity example can be explained by looking $HCl$ molecule in which $C{l^ - }$ is an electronegative atom whereas ${H^ + }$ is electropositive and the bond so formed is covalent. Electronegativity is the property in which an atom can attract shared pairs of electrons towards itself.

Complete step by step answer:
We need to know that an atom’s electronegativity is affected by both atomic number and valence electrons inside the nucleus. Electronegativity increases when on moving from left to right and decreases on going down the period. In halogens, i.e. group $17$, the position of elements in a periodic table is:
$F$, $Cl$, $Br$ and $I$
$F$ is the most electronegative atom in the group $17$ $Cl$ being more electronegative than $Br$ and less electronegative than $F$.
When we move down in a group, the atomic number increases as the atomic shell is increased, hence the effective nuclear charge increases due to which electronegativity decreases. Metals usually have lower electronegativity as they are electropositive in nature.
For Example: $Na$, $Sr$
Also due to the electronegativity concept we can refer to the covalent bonding in certain molecules. Since covalent bond is formed by two molecules having different electronegativity in which more electronegative atom forms anion and least electronegative atom forms cation.
Option A) this option can be correct as electronegativity is the tendency of an atom to attract the shared pairs of electrons.
Option B) this option can be correct $F$ is more electronegative than $Cl$ as down the group electronegativity decreases.
Option C) this option can be correct as on moving down group electronegativity decreases.
Option D) this is a correct option as all the options given above are correct.

Hence, the correct answer is, ‘Option D’.

Note: We need to remember that the elements that have low ionization energy will have low electronegativity and electronegativity is inversely proportional to atomic radius. This follows the periodic trends observed in the periodic table.