Question

$\left(\mathrm{a}\right)$ The electropositive nature of the element(s) increases down the group and decreases across the period

$\left(\mathrm{b}\right)$ Electronegativity of the element decreases down the group and increases across the period

$\left(\mathrm{c}\right)$ Atomic size increases down the group and decreases across a period (left to right)

$\left(\mathrm{d}\right)$ Metallic character increases down the group and decreases across a period.

Based on the above trends of the periodic table, answer the following about the elements with atomic numbers $3$ to $9$. Name the most electronegative element.

Answer 1

Electronegativity:

1. It is the tendency of an atom in a molecule to attract the shared pair of electrons to itself.
2. Electronegativities tend to fall from top to bottom within a group as atomic size increases, i.e. the larger the atom, the lower the electronegativity.
3. Because the electron is introduced in the same shell, the nuclear charge increases and the atomic size reduces as we move from left to right across a period in the periodic table, the electronegativity increases.
4. The element with an atomic number $9$ i.e. Because electrons are strongly attracted to the nucleus, fluorine is the most electronegative element. It also has a smaller size than the other elements.

Therefore, the element with an atomic number $9$ i.e. Fluorine is the most electronegative element.